


Derek's Baby Boy--Kate AU

by GentlyWithAChainsaw



Series: Derek's Baby Boy [3]
Category: Teen Wolf (TV)
Genre: AU, Diapers, Disturbing elements, Forced infantilism, Humiliation, Multi, Non-Con Age Play, Non-con touching, Pacifiers, Rape/Non-con Elements, Revenge, Sex Toys, Spanking
Language: English
Status: Completed
Published: 2016-05-01
Updated: 2017-09-23
Packaged: 2018-06-05 16:30:00
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 6
Words: 32,497
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6712561
Author URL: https://archiveofourown.org/users/GentlyWithAChainsaw/pseuds/GentlyWithAChainsaw
Summary: <blockquote class="userstuff">
              <p>A dark alternate universe in the Derek's Baby Boy series, where Derek finds a creative way to take revenge on Kate.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Since this is becoming a monster fic, and it's way darker than anyone else, I'm giving it it's own place. First chapter is reposted for convenience.  
> This is not a nice story. It's dark and messed up and where the darkest prompts go. Please pay heed to the rape/non-con tag.

“Daddy, can I tell you a secret? I have a secret, Daddy!” 

“Okay, pup, what’s your secret?” Derek sticks the last empty bottle into the dishwasher and starts it up, Stiles on his hip. Today the baby is feeling clingy, so Derek is carrying him around as he cleans up. 

Stiles leans in until his lips are centimeters from Derek’s ear. “Cranberry juice is my favorite,” he whispers. 

Derek hides a grin. “I thought it was orange juice.” 

“Was last week but then Uncle Peter only had the juice with pieces, that’s yucky. No pieces in cranberry juice.” 

“How about Daddy gets you some juice now?” 

Stiles nods happily. Derek grabs a sippy cup and fills it with juice before giving it to Stiles. Stiles sucks on it noisily, resting his head against Derek’s shoulder. “Daddy, I like cranberry juice even betterer than milk.” 

“But milk keeps you nice and healthy, pup, so you have to drink that every day.” Derek’s cell phone rings and he digs in his pocket with his free hand. “Hello?” 

“Derek? This is Olivia Jones with the Society.” 

Derek frowns. He hasn’t spoken to Olivia since he was going through the adoption process for Stiles. “Hi, Olivia. What can I do for you?” 

“Daddy, who is it?” Stiles asks loudly. 

“Well, I know this is a bit unusual, but…” Olivia takes a deep breath on the other end of the line. “We found her, Derek. Kate Argent. She was living with other hunters. We attacked and killed most of them, but she survived with a few others.” 

Derek freezes. He’d been telling himself for years that Kate was dead. It was the only way he knew to get through the days. “You— you’re sure it’s her?” 

“Yes. We thought about simply putting down the survivors we have in custody, but I thought you might like to make the decision here. We can put her down now, wait for you and your uncle to get here so you can watch, or…work out some other arrangement.” 

“You mean…keep her?” 

“I suppose you wouldn’t want to give her too much agency, but there are plenty of ways you could keep her as a pet. Or another baby, I know you’ve been enjoying your little one. It’s completely your decision. Whatever would help give you closure.” 

Derek closes his eyes. He’d been so happy thinking Kate was gone forever. A part of him just wants to tell Olivia to put a bullet in her head so he can stop thinking about her. 

But then he sees her in his mind’s eye. Those wild eyes, glowing with triumph in the light of his burning house. Her laugh dancing on the wind. He doesn’t just want that laugh silenced— he wants it replaced. 

Replaced with a high, insistent cry for Daddy, a soft coo, the sweet babbles he remembers from when he’d aged Stiles down. He thinks of Kate dressed in nothing but a diaper with her hands in mittens. She would hate it so, so much. She would hate it for years. But eventually she would give in— forget who she used to be. His mouth is dry at the thought of it. 

“I think we can work something out,” he says hoarsely. 

X 

Kate is ready to die. 

Honestly, when the wolves had stormed in she’d expected nothing less. There had obviously been too many of them, so there was only one way the fight could end. 

Much to her horror, they took hostages. They haven’t even tortured her for information yet. They’ve just left her tied to a bed, completely ignoring her. 

God, she hates werewolves. 

She tries to free her hands one more time, but no luck. She groans just as the door opens and a female werewolf walks in. 

Finally. Kate tenses, expecting to be taken somewhere and tortured or killed, but the werewolf does something completely unexpected. She smiles. 

Kate pulls back her own lips into a grimace. 

“Oh, none of that,” the woman chides, bending down over Kate. “I think you have lots of reasons to smile, sweetheart. We’ve finally figured out what to do with you. You’ve been given a second chance, isn’t that wonderful?” She pulls a bottle and a syringe out of the pocket of her lab coat. “Now you need to have a little shot, just to keep you still.” 

Her voice is gentle and sort of high-pitched. Kate doesn’t understand and can’t move at all as the woman injects her. She immediately feels like thick lead is spreading through her veins. She can’t even moan as the woman unties her from the bed, puts her in a wheelchair, and wheels her out of the room. 

Her eyes have drifted shut by the time the ride finally ends. She feels sort of faraway and floaty, but she can still hear. “Is this our little one?” a man’s voice says as Kate is lifted from the wheelchair and placed on some kind of cot. 

“Well, she will be soon.” A hand strokes Kate’s hair away from her face. 

“I don’t know if he’ll be able to do this. I certainly couldn’t. I can love the innocent humans, but it’s hard to put my feelings towards their kind aside.” 

“Now, now, that’s what makes us better than them. She’ll never hurt anyone else again. We’ll treat her just like any other baby.” Kate realizes with horror that she’s being undressed. “But first we have to get rid of all this yucky hair, don’t we?” 

The man laughs. “You don’t have to talk to her like that, she’s totally out. She can’t hear you.” 

“You don’t know that.” Someone is rubbing something on Kate’s legs and— oh God— over her pubic hair. “We need to make all this skin nice and soft, don’t we? Oh, yes, that’s much better. He wanted her to have the full array of shots, right?” 

“Right. No mobility, no bladder control, and most importantly, no voice. He wants her to only communicate by crying.” The woman is still running her fingers through Kate’s hair. 

The man snorts. “Something tells me that no matter what he says he won’t be treating her like any other baby.” 

“Yeah, but can you blame him?” The woman’s voice gets far away as Kate drifts farther off into unconsciousness. Her last rational thought before she’s under completely: 

What the hell is going on? 

X 

Daddy has been acting funny. For the past few days he’s been having lots of private conversations with other werewolves, and there’s something going on in the spare bedroom upstairs. Stiles is starting to get a little upset because Daddy is barely paying any attention to him. 

He’s thinking about maybe throwing a little tantrum just as Daddy comes and gets him from his nap and carries him over to the rocking chair. “I have some news for you, little prince,” he says, stroking Stiles’ hair from its sleep-mussed state. 

“What, Daddy?” 

“You know that you’re my favorite little boy in the world, right?” 

Stiles smiles, of course he knows that. “Uh-huh.” 

“And Daddy could never, ever love any other baby as much as you. But Daddy has decided that our family should be a little bit bigger, so guess what? You’re going to get a baby sister.” 

Stiles’ mouth falls open. He knows his friend Johnny has a baby sister, but most of his friends are the only baby in their family. “Who, Daddy?” 

“Her name is Katie. She’s waiting for us to pick her up tomorrow. Now, she’s a very, very little baby. She’s going to be fussy for a long time, but I know you can be my good boy and show her how to behave.” 

“Like with Ally?” 

Daddy smiles. “Very much like Allison. But she’s going to be a naughty little girl, much naughtier than Ally ever was. I need you to promise me that you’ll keep a close eye on her and tell Daddy if she’s misbehaving.” 

Stiles puffs up with importance. “Promise, Daddy!” 

Daddy smiles. “Good boy, Stiles! Would you like to see her nursery?” 

“Okay.” Stiles feels kind of nervous as Daddy carries him to the spare room. He knows he’s Daddy most favorite boy in the world, but what if Daddy loves the new baby more than him? She’s going to be so little that Daddy will have to give her lots of attention, and maybe he won’t have time for Stiles anymore. 

Daddy pushes open the spare room door and Stiles’ mouth drops open. It smells like paint and it’s been completely transformed. It’s painted the color of cream and there are pink letters on the wall spelling out KATE. There’s a crib and a changing table all covered with frilly pink lace and another rocking chair with a big floppy bunny. Everything has thick straps. “It’s nice, Daddy,” Stiles says approvingly. He can see a picture on the wall blown up of big, up towards the ceiling so the baby will be looking right at it in her crib. “What’s that?” 

“That’s a picture of the people who used to be in Daddy’s family.” Daddy walks him over towards the picture so he can see. Daddy’s in the picture, but he looks really young, and there’s Uncle Peter, and there are lots of people Stiles has never seen before. 

“They look nice, Daddy.” 

“Yes, they were.” Daddy stares at the picture. His face is hard for a second, but then he looks at Stiles and smiles. “And they would have loved you, sweetheart.” 

“And the new baby?” 

Daddy looks sad. “No, they wouldn’t have loved her. Right now the new baby is a very naughty girl. Remember how we talked about how most humans are bad? Little Katie has been with humans for a long time, so she’s not a very good girl. But we’re going to teach her to be a perfect baby, and then everyone will love her.” 

Stiles feels better about the new baby after that. His Daddy is so nice, helping a bad human be a good little baby. “When can I meet her, Daddy?” 

“We’ll leave to go get her early tomorrow morning.” Daddy kisses him as they leave the nursery. “We’re going to be very happy,” he says softly, voice filled with so much satisfaction that Stiles can’t help but smile in return. 

X 

Kate drifts for a long time, dimly aware of the pinpricks of a syringe every so often. She’s just starting to wonder if this is her punishment, to be kept unconscious for the rest of her life, when she finally feels herself starting to swim back up to the surface. 

She realizes with faint worry that even once she can move her hands she can’t really feel her legs. But that’s something she’ll have to worry about later. 

“— asleep for a while now, but she should be opening her eyes any moment,” she hears a voice say. 

“She’s been given all her shots?” 

“Yes. They’ll last for six months.” 

Kate…recognizes that second voice. She thinks. It’s hard to tell with her eyes shut like this, but she struggles to open them. “There we go,” the first voice coos. “She’s a sleepy little thing right now.” 

With a great effort Kate’s eyes finally open and adjust to the light. There’s a woman leaning over her, smiling, and behind her— 

Kate screams. This isn’t real. This can’t be happening. It’s been years, and she’d run as far away as she could, and her family said the survivors of the fire had fled and never returned. But it’s Derek standing there, now fully grown. He’s holding a teenage boy in his arms but Kate barely focuses on that. She can only stare in mute horror at the man who must be here to kill her. 

But then Derek smiles. He smiles and bends down, picking her up with one hand. He nestles her against his shoulder, legs bunched up by his chest. The fact that he’s holding two fully grown people in his arms doesn’t seem to be fazing him at all. “Oh my goodness,” he says softly. “It’s been a while, hasn’t it, Kate?” 

The other boy is staring at her with interest. “This is my baby sister, Daddy?” 

“Yes, this is Kate. Give her a kiss to say hello.” 

The boy leans forward and gives her a wet kiss on her cheek. She can’t move at all to shove him away, it’s like she’s completely paralyzed. “Hi,” the boy says happily. “I’m your big brother Stiles, I’m going to help you be a good baby!” 

Kate looks at Derek in horror. Derek smiles at her. “That’s right,” he says, still in that gentle voice. “You’re never going to hurt anyone again. For the rest of your life you’re going to stay with me and your big brother. After all the naughty things you’ve done you can’t be trusted to behave like an adult, so you’re going to be a little baby now.” He tugs at the blanket around her until it’s loose, then reaches down until she can feel that she’s wearing a diaper. “You’ll wear one of these every day, and you’ll drink from nice bottles, and I’ll take care of your every need.” 

Kate tries to snarl at him. She wants to taunt him, remind him of what she did to wipe that smile off his face, but all that comes out is a high mewling sound. She can’t talk, she can’t move— 

Derek lays her down and takes the blanket off completely. There’s a binding around her breasts that Derek ignores as he shakes out a pink onesie and lays it down next to her. “Did the little girl wet her diaper?” he asks cheerfully as he unwraps the diaper too. “Olivia, can you hold Stiles so I can take care of little Kate?” 

The boy is transferred into the woman’s arms. Kate can hear him giggling, apparently unaware of how completely fucked up this all is. Kate is completely unable to move as Derek separates the folds of her vagina with two fingers and clinically rubs inside of her. “Hm, looks like she’s still dry.” He takes his fingers away and instead rubs his hand over her thighs, which have been completely removed of any hair. Kate shivers, remembering the last time Derek touched her like this. 

He puts on a new diaper and dresses her in the onesie. Then he raises each of her hands and puts on mittens, pulling a drawstring so they’re tight. Kate whimpers again and Derek clucks. “None of that. Let me make one thing clear. We’re not ever going to talk about what happened before. I’m not your victim or your boyfriend anymore, Kate.” Derek smiles, a wide, vindictive, joyful smile. “I’m your Daddy now.” 

X 

She looks exactly the same as Derek remembers. A few more lines on her face, maybe, but the same hair, same eyes, same mouth… 

He can’t stop staring at her as the driver takes them back to his plane. Stiles is talking to her excitedly about her new nursery and toys and how much she’s going to love her Daddy and Kate’s eyes flicker around in terror as she slowly realizes she’s completely trapped. 

It’s going to be very important to reassure Stiles that he’s still Derek’s favorite, so he makes sure to hold the boy close and let the Society driver carry Kate onto the plane. “What do you think?” he asks Stiles softly once they’re inside. “Do you like your new little sister?” 

Stiles shrugs. “Will she be able to play someday, Daddy?” 

“Someday, maybe. Now, because I know you’re going to be such a good big brother to your new sister, Daddy bought you a special present!” Derek takes Stiles to the back of the plane where he’s stashed the gift. It’s a new teddy bear wearing a Big Brother t-shirt, plus a book written by the Society specifically for babies who are having a new member joining the family. “We’ll read this on the plane, okay, sweetheart?” 

Stiles nods happily, hugging his bear. Derek walks over to help buckle Kate into the car seat built into the plane before tipping the Society rep and settling into a seat with Stiles. “Daddy, she needs a pacifier so her ears won’t pop,” Stiles reminds him. 

“That’s right! You’re so smart, pumpkin.” Derek pulls a pacifier out of his pocket, sticks it in his own mouth to make sure it’s clean, then slides it into Kate’s mouth. She tries to clamp her jaw shut but he just chuckles and rubs his thumb along the hinge of her jaw until she can’t help but open up. He gives Stiles a pacifier too and settles in, feeling very satisfied as the plane takes off. 

While they’re in the air he reads the new story to Stiles. He knows Kate is listening too, so he gives plenty of extra details that aren’t in the book. “This page is all about how to keep little babies clean,” he tells Stiles. “Kate will need lots of baths and diaper changes.” 

He can smell, in fact, that Kate’s incontinence shot is working and she’s wet the diaper, but he ignores it for now. He remembers how obsessed with cleanliness Kate used to be. She would always shower after sex. Maybe it was because he was a werewolf and disgusted her— but now he’ll make sure she disgusts herself. “This page shows how to swaddle babies to keep them calm,” he tells Stiles. “We need to make sure Kate is wrapped up nice and tight so she can’t move.” 

When the plane touches down he carries his babies out to the car. He’s put a new rear-facing car seat in for Kate and he straps her in, feeling the lump in her diaper that means she’s used it from both ends. He wonders how long it will take before she finally gives in and lets her pride go and whimpers for a change. 

Stiles naps on the way home but Derek knows Kate is wide awake. He can hear her panicked heartbeat and the sound is deeply soothing, like it’s scratching an itch he’s had for so long he’s almost forgotten it was there. 

X 

God, why hadn’t they just killed her? Kate wishes with all her heart they had just killed her. 

She’s sitting in her own waste— she’d been unable to control herself, it just came out of her without her control. Derek has placed her in some kind of giant bouncer so she’s sitting up. He’s currently playing with the other boy, Stiles. Stiles’ childish giggles are getting under her skin, spooking and irritating her until she wants to just scream. 

Eventually the boy wins whatever game they’re playing and Derek rolls over onto his back so he can lift the boy into the air. The boy shrieks in delight, pin wheeling his arms and legs. “You’re my favorite little baby in the world,” Derek croons to him, kissing his forehead and cheeks. 

“Again, Daddy, again!” 

Derek laughs and lifts him again. Kate can’t stand it. He’s happy. She’s imagined that Derek, if he survived, was off being miserable somewhere, but whatever sick fantasy he’s living out right now is clearly exactly what he wants. And now he’s fitting Kate into it. He's finally getting his revenge, and she can only guess at what his plans for her are. 

She has to get out of here. Now. 

Finally Kate feels herself use the diaper again and she just has to whimper. She has to get it off of her, regardless of how humiliating it is. Derek comes over to bend down next to her, still holding Stiles. Stiles wrinkles his nose. “Daddy, she did a yucky.” 

“I know, pup, she’s a messy little baby.” Derek lifts her from the bouncer. “Daddy will go make her clean while you play down here.” 

Kate wants the diaper off, but she still feels like screaming and thrashing as Derek carries her up the stairs. “Wait until you see your nursery,” Derek coos. “But I think, since you’re so new and little, it would be best if you slept in your bassinet for a while. That’s in Daddy’s room.” 

He pushes open a door and walks her inside a cream-painted room. “It was so nice getting your nursery ready for you. Daddy bought you lots of clothes and toys. And here, look what Daddy put up.” He walks her towards one of the walls and she sees a picture of the Hales. “Now you’ll have lots of people watching over you,” he says, voice viciously satisfied. 

She’s plunked down on a changing table and Derek strips off the diaper. He makes a small amused sound as he wipes her off. “What a filthy little girl,” he croons. “Next time you’ll have to call for Daddy sooner, won’t you? I’d hate to see you get a rash. Then Daddy would have to put cream all over your little yum-yum.” He turns her over and starts to wipe clean her vagina. “There! All better.” 

She hears herself make an angry little sound and Derek chuckles. “Oh, little girl, you shouldn’t even try that. There’s no point in being angry, because there’s not a single thing you can do. Look at this!” He takes off one of her mittens and unfurls her fingers so her palm is laying up. He places his finger on her palm and she clutches it instinctively, unable to stop herself. Derek chuckles again. “Look at you grabbing Daddy’s finger! No more fists or yucky weapons for you, you’re just a helpless little baby now. Daddy can do whatever he likes to you. So you might as well behave.” He puts her into a new onesie and carries her back downstairs. 

Once again she’s placed in the bouncer and Derek goes back to playing with Stiles, lavishing attention and affection on him. Kate tries to move her fingers, figuring she just has to start getting mobility back somewhere and maybe the rest of her body will follow, but nothing happens. 

She doesn’t know exactly where she is, but the hunters have been suspecting for a while now that werewolves have been living away in secret. They hadn’t known that they were brainwashing humans and keeping them here like this. Maybe other hunters will figure it out. Maybe they’ll find her. Maybe… 

“Daddy, maybe Katie did a yucky again,” she hears Stiles say. “Remember that little babies have to be kept clean, that’s what the book said!” 

“That’s a good idea, pumpkin. Do you want to help me check?” 

“Uh-huh!” 

Derek comes back over and lifts her from the bouncer before laying her down on a crinkly playmat on the ground. Kate can feel her cheeks flame bright red as Derek undresses her again and untapes the diaper. “Daddy, she looks funny down there,” Stiles says with his brow furrowed. 

“That’s because she’s a girl, sweetheart, and you’re a boy. She doesn’t have a pee-pee like you, she has a yum-yum. Would you like to feel?” 

Stiles nods and Derek guides his hand. Kate can feel the boy poking clumsily around her vagina. It’s horrible and embarrassing, but she can’t help but respond to the attention. “Daddy!” Stiles says, sounding scandalized. “I think she’s going pee!” 

Derek laughs. “No, pumpkin, she’s just getting wet. That’s what happens to girls when someone is giving their yum-yums attention. It means she’s starting to feel good, like you do when Daddy gives you special touches. What do you think? Should we keep helping her feel good?” 

Stiles nods again and keeps rubbing inside her vagina. Derek’s fingers slip in next to him, focusing right over her clit, and Kate hears herself gasping and whimpering as they mercilessly push her to orgasm. “There we go!” Derek says when it’s over. “She really liked that, didn’t she, Stiles? We’ll have to make sure she gets lots of nice touches to help her settle in.” 

Kate closes her eyes as Derek tapes her diaper back up. “Now she’s sleepy,” Derek tells Stiles. “Daddy will go put her in her bassinet, and then we’ll have some more Stiles and Daddy time before you go beddy-byes.” 

She lets herself go limp as Derek carries her back upstairs and takes her into his bedroom. He puts her into a bassinet, using straps to keep her tied down. “I know these are so unnecessary,” he tells her in that awful, soft voice. “You can’t move anyway. But do you want to know a secret? I really like seeing you all strapped down into your bed.” He kisses her forehead as she tries with everything in her to jerk away. “Now, I’m going to go play with your big brother some more, we certainly don’t want him feeling neglected. He’s my special boy. We live here with lots of other werewolves, and lots of humans are here with us. Wait until you meet our neighbor’s little girl, I bet you’ll like her!” 

He spins a mobile over the bassinet and little lambs start to prance over her head. “Get some rest,” he tells her. “We’ll have lots of fun once you wake up tomorrow morning. I know you’re going to be so fussy for a while, but you’re not stupid, are you Kate? You’ll realize soon enough that there’s no way out and you just have to accept where you are.” 

He kisses her one last time. “Sweet dreams, little one,” he whispers. Kate stares up at him helplessly, unable to move as he leaves her in the bassinet alone.


	2. Chapter 2

Kate prides herself on one thing: the ability to fall asleep in almost any situation. No matter how stressed, scared, or uncomfortable might be, she can always turn it off and get several hours of blissful unconsciousness. 

Her first night in Derek’s house that’s exactly what she does. She forces herself to ignore the straps and fear and falls asleep right after he leaves the room. She sleeps without dreaming through the night and wakes up the next morning disoriented, trying to remember where she is. 

_Derek. Diaper._ She feels herself grimace with fury. _Asshole_. 

After her long night of sleep she feels a little better about her situation. This is just a minor little setback for her. She can get out of this. And hell, now she’s in a town filled with werewolves. She will lay _waste_ to the place before she’s done. 

The thought gives her a moment of satisfaction before she realizes that she must have used the diaper while she was asleep. Her skin feels itchy and disgusting but she clamps her mouth shut. She will _not_ cry out and give Derek the satisfaction. 

She hears something, a crackly burst of sound like it’s coming through a walkie-talkie. “Daddy! I’m awake now.” 

There’s a small chuckle from Derek’s bed and creaking as he gets up. She shuts her eyes quickly so Derek won’t know she’s awake. 

She’s alone for about five minutes before Derek returns. That boy is with him now. “Is my sister asleep?” he asks in an exaggerated whisper. 

“Mm-hmm, we’ll have to make sure we don’t wake her.” Derek lays back down on the bed with Stiles. “You were such a wonderful big brother last night, helping her feel so good. Daddy’s so proud of you. Should Daddy help _you_ feel good now, as a reward?” 

The boy makes an excited sound. “Please, Daddy?” 

“Okay, pumpkin.” There’s a rustling and then the unmistakable sound of a man being jerked off. Stiles makes a happy sound, almost like a coo. “D-Daddy, harder.” 

“I don’t think you need it any harder, pup, you’re already getting sticky.” The sounds increase, the boy panting along until he finally lets out a loud moan. 

_Disgusting_ , she thinks, shutting her eyes tight and trying to fall asleep again. 

“Daddy, ‘m all yucky now.” 

“Don’t worry, Daddy has wet wipes.” Derek cleans him off, then makes those annoying loud _mwah mwah mwah_ sounds that adults do when they’re kissing babies. “You are such a perfect little prince,” he says adoringly. “Daddy loves you so much.” 

The boy coos again. “I love you too, Daddy!” 

They’re quiet for a few minutes, but Kate can feel their contentment in the air like a smog. It infuriates her. Derek isn’t supposed to be like this, he’s supposed to be suffering. She tries to go to her happy place, the Hale fire and those beautiful screams from inside the house. The glimpse she had of Derek running towards his home with wild devastation in his eyes. But whenever she tries to picture it all she can see is that poster of the Hales Derek had shown her yesterday, staring down at her humiliation like they’re getting the last laugh. 

“Daddy, maybe Kate needs a diaper change,” Stiles says. “We should check.” 

_Yes, please._ Kate might scream if she has to wear this filthy diaper a moment longer. 

“No, sweetheart. Kate needs to learn that when her diaper is dirty she has to do what babies do and cry for Daddy to come and help. If Daddy just did that for her she would never learn how to behave.” 

Stiles sounds confused. “Did I learn that, too?” 

“Oh, of course not! Daddy would never let _you_ sit around in a messy diaper, pumpkin. Daddy always changed you right away, even when you were brand new. But you and Katie are different. Remember how Daddy always tells you that the reason you’re here with me is because you’re such a sweet, innocent little boy who needed to be _rescued_ from all those bad humans? Well, Kate is one of those bad humans, so we’re giving her a chance to start over. She needs to forget that she was ever a grown-up who did such naughty things. Sometimes you might think Daddy is being mean to Kate, but it’s not to be mean. She needs to be treated this way so she can learn to be a perfect little baby.” 

“Okay,” Stiles says, as if Derek is explaining the most natural thing in the world. “I’m hungry. Can I have a bottle, please?” 

“Of course you can. Just let me turn on Kate’s baby monitor so I can hear when she cries.” 

Kate never lets people see her cry, that’s one of the core principles by which she lives. She’s so angry as Derek and Stiles leave the room that she realizes Derek _must_ be able to hear it in her heartrate. He knows she’s awake. This is all just part of his torture. 

Well, fuck him. She’ll just stay here silently all day. She keeps her eyes closed, trying to shut out the feeling of the diaper. It’s impossible to fall back asleep so angry, and the more she tries to ignore the diaper the more conscious of it she is. 

Worst of all, her stomach is starting to growl. She’s starving. Kate has never handled hunger well. She hears herself make a tiny sound of frustration. Maybe she could be just a _little_ louder. She’s not really _crying_ , of course, but it’s pointless to lay here in her own waste for hours. 

She lets out a rattling cry, hating herself when she hears how high-pitched and insistent it is, just like a baby needing attention. Within moments Derek is there, bending over her with a self-satisfied smile. “Yes, Kate? Did you need Daddy?” 

She glares at him as he lifts her from the bassinet and wrinkles his nose. “What a dirty girl you are! You’re such a silly little baby, you don’t even know how yucky it is to sit around in a messy diaper.” 

Kate is very pleased to find that whatever is paralyzing her extremities hasn’t affected her ability to roll her eyes. Derek carries her back to that cream-colored nursery and takes off the diaper. “You’re going to get a rash,” he says chidingly. “Then a diaper would be too painful, so Daddy would have to carry you around completely naked. You don’t want that, do you?” 

He changes her briskly and efficiently, not touching her any more than necessary today, before putting on a new diaper and going over to the dresser. The onesie he picks out is pink with polka dots and the words _Little Pup_ in flowery writing. Kate wants to gag. “We’re going to have to cut this hair,” Derek says as he dresses her. “Long hair might be pretty on big girls, but it’s just a hassle for little babies. Maybe we’ll shave you as bald as a newborn. That would make bathtime easy, wouldn’t it?” 

He props her onto his hip, but she can’t support her own head and her neck snaps backwards. “Whoopsies,” Derek says, giving the word a mocking twist. “Silly Daddy forgot how teeny-tiny you are.” He changes positions so she’s cradled in his arms and carried her downstairs. 

She can smell food from the kitchen, definitely bacon or sausage, and she practically drools. Stiles is there in a high chair nibbling a piece of bacon. Kate doesn’t even care how embarrassing it would be to be hand-fed, she desperately wants food. 

“Now, you need a nice big bottle for breakfast, don’t you?” Derek baby-talks to her, grabbing a baby bottle from the dish drainer with his free hand. It takes Kate a minute to realize what he’s saying, but when he fills the bottle with formula and puts it to her lips she gets it. This is all she’s supposed to have for breakfast. She can’t hold back her anger and lets out an enraged shriek. 

“Daddy?” Stiles asks nervously. “Is she okay?” 

“She’s having a temper tantrum. Sh, sh, Katie. This is just the right breakfast for a little girl. It’ll fill up your tummy, I promise.” He keeps pushing the bottle into her mouth and she keeps her lips sealed, straining away as best she can. 

“Can I help, Daddy?” 

“No, sweetheart, but thank you. If she doesn’t drink her bottle Daddy will just have to force-feed it to her.” The threat is obviously meant for Kate’s ears and she goes still, reluctantly closing her lips around the nipple and sucking. God, it’s so _disgusting_. Grainy and too-sweet and thicker than any milk she’s ever had. He’s right about one thing, though: she’s full even before the bottle is empty. She still wants real food and the realization that this is all she’s getting for the foreseeable future is almost painful. 

Derek turns her and pats her back for a while until she burps. Derek praises her for being such a good baby and drinking all her milk, and somehow it’s almost worse than the gloating. Tears spring to her eyes and she tries to blink them away before he can see. 

After breakfast Derek takes her and Stiles into the living room. Stiles is placed on the floor next to what looks like a trunk full of toys, surrounded by dolls and blocks and books. Derek sticks Kate into the baby bouncer, strapping her in until she can’t even wriggle, before bending down next to Stiles. “Daddy’s going to finish up some work in Katie’s nursery,” he tells the boy. “Can you look after your little sister while I’m gone? Just make sure she’s sitting quietly like a good girl.” 

Stiles beams at him. “Uh-huh!” 

“Thank you, sweetheart.” Derek kisses the top of his head and leaves the room. Stiles returns to his toys, glancing at Kate every so often, before crawling over to her and smiling timidly. “It’s okay, Katie,” he whispers to her in his sweet little-boy voice. It’s unnerving to hear a voice like that coming out of someone who must be in his late teens or early twenties. God, Kate hates idiots. “I know it’s really, really hard to be good when you’re brand-new. I used to have temper tantrums too, Daddy said. But I’m your friend, okay?” He shyly holds out a toy to her. It’s a doll styled to look like a mermaid, with an orange tail and purple hair. “Do you want my mermaid? Her name is Calliope. We can play with her together, if you want! I’ll show you.” He puts the doll into her hand, gently closing her fingers around it. “My mermaids are my very favorites, but we can share!” 

Kate is pleased to see that she’s able to make a fist and hold onto the doll. Although her range of motion is limited she can drop her hand, so the doll’s tail is balanced against the floor. 

Stiles giggles. “Nuh-uh, Katie, that’s not how you play! You have to make her swim.” 

Kate presses the doll against the floor. There’s a hinge between the tail and torso where the doll bends and she pushes until the doll is bent as far backwards as it will go. Her muscles are weak but the floor does most of the work for her. 

“N-no, Kate.” Stiles sounds nervous now. He tries to grab the doll but she holds on tight. “That’s not—” 

The doll breaks in two with a satisfying crack. Kate lets the two pieces fall to the floor, glorious satisfaction spreading through her veins at the shocked, almost sick look on Stiles’ face. It’s been _far_ too long since she’s broken something, since she’s hurt someone like this. It feels good. 

Derek must be listening in because he swoops into the room within seconds. “What’s going on here?” His gaze falls on the broken doll. “Stiles?” 

Stiles stares at the doll, face white. “She broke Calliope,” he whispers. “She— she _killed_ her.” 

Derek glares at Kate and picks Stiles up, cradling him with one hand on his back. “Sh, sweetheart. It’s all right.” 

“Sh-she killed…” 

“Daddy can fix Calliope, pumpkin. Sh, it’s okay.” 

“Was it— did she do it because I’m bad?” Stiles’ voice sounds different— older, but somehow even more fragile than before. “My toys— she used to break my toys when I was bad. I remember. The bad lady used to…” 

“No, Stiles. Sh, we don’t think about that bad lady anymore, remember? She’ll never hurt my little prince again, not now that he’s here with Daddy.” 

Stiles’ voice cracks. “I didn’t mean to be bad!” 

“You didn’t do anything bad. Kate’s the bad one. Daddy will punish her for what she did and she’ll never do it again.” Derek kisses him, both of them completely ignoring Kate. “Calliope will be just fine, Stiles. Daddy will fix her right up.” 

“I’m s-sorry, Daddy, I shouldn’t have given her to Kate, but I thought m-maybe if she had toys she might be h-h-happier.” Stiles’ voice trails off into sniffles and Derek cuddles him, a gentle look on his face. 

So he does really love the boy. Good. Kate is going to use every ability she still has to torture the brainwashed little idiot. And when she breaks free, she’ll burn down _this_ house with him still inside. 

“Here’s what Daddy’s going to do,” Derek tells the boy once the sniffles have stopped. “First I’m going to take Kate upstairs and put her in time-out. Then I’ll make Calliope all better. Then we’ll have some yummy ice cream, all right?” 

The last part seems to perk Stiles up. “For _lunch?_ ” 

“Yes, ice cream for lunch. Just for Stiles and Daddy.” Derek kisses Stiles’ forehead one more time. “Don’t worry, pup, she won’t be naughty forever. Soon she’ll be happy to play with you and your toys, I promise. You’ve met new babies before, haven’t you? And they all became good little boys and girls soon enough.” 

Stiles sniffles, but nods. “Like my Allison,” he says. 

_Allison_. The name hits surprisingly hard. Kate hasn’t thought of her niece in a long time; hasn’t really wanted to. Her brother had made it clear that Allison didn’t need people like Kate in her life, and Kate had cut ties with her family when she ran off with more…dedicated hunters. None of the Argents except herself and her father had the balls to really dedicate themselves to the eradication of werewolves, but Chris was the most boring of them all. 

Still, Kate has fond memories of her little niece. It’s been years since she’s seen Allison; she must be old enough to be receiving her training by now. Maybe she’ll end up being among Kate’ rescuers. Then they can kill all the werewolves in his town together. The thought cheers her up and she gives the boy the most malicious look she can manage as Derek picks her up and carries her from the room. It feels good to give herself a purpose. She might be too compromised to fight Derek right now, but she can hurt the person he cares about. She’s done it before, after all. She’s really going to enjoy doing it again. 

“What are you smiling about?” Derek asks softly when they reach the nursery, his voice back to normal. “Proud of yourself? You shouldn’t be. That was a stupid thing to do. Not that I’m complaining— I knew you would do _something_ if I left you in the room with him alone. He’s got too big a heart for his own good, and I knew he wouldn’t be willing to believe the truth about you. But you sure showed him, didn’t you?” 

He puts her into the crib, using straps to tie her arms and legs to the bars. “Now I get to fix his doll and be his hero. You have no idea what it is to be _adored_ like that, do you, Kate? Sure, I used to be infatuated with you, but I never looked at you like you hung the moon the way he looks at me. Being loved that way makes me happier than I’ve ever been. And having you here to watch it just makes this life perfect for me. In a few years— or decades—torturing you might start to get boring. But I’ll never be bored with knowing you’re watching me enjoy everything you can never take away.” 

With a tiny smirk on his face he leans into the crib and kisses her forehead. “This is the last grown-up conversation we’ll ever have,” he tells her. “The last grown-up conversation you’ll have with _anyone._ Because Kate— _I win.”_

He steps away from the crib and bustles around by the dresser. When he comes back his voice has changed, back into the high-pitched baby-talk. “Now the little girl needs to wear her mittens, since she doesn’t know how to use her hands properly.” He fits the mittens onto her hands, drawing them tight. “Katie has to spend twenty minutes in time-out.” 

She snarls up at him while he latches a cover onto the crib, until she feels like she’s in a cage. “Now, now,” Derek says cheerfully. “If my little girl doesn’t start smiling soon, Daddy will have to put her pacifier back in. That wouldn’t be any fun, then she couldn’t even call for Daddy when she needs help!” 

He turns on some kind of ocean sounds machine and leaves the room. Kate goes completely still, keeping her eyes shut until she can force herself to fall asleep. 

She’s not even out long enough to dream before Derek is back. “Were you napping?” he coos as he unties her arms and pulls her from the crib. “Time-out is over now. Let’s go back downstairs.” 

He carries her back to the living room and puts her in the bouncer again. Stiles is still there— when he sees Kate he gathers up the rest of his mermaid dolls, holding them protectively as he eyes her warily. This time when Derek leaves he doesn’t smile at her or come near her. It all gets boring pretty fast, but she forgets about the boredom when she realize her bladder is full again. 

Before she can even try to hold it in she can feel herself soaking the diaper, completely unable to control herself. She doesn’t understand why her body is betraying her like this. For a moment her lip wobbles and she considers yelling to get Derek to come and change her, but she tries to hold back. She won’t let him take her pride. 

She hears Derek reentering the room and watches as he bends down next to Stiles and holds out the doll Kate had broken, the hinge now fixed. Stiles’ eyes go wide as saucers. “Daddy! You fixed her?” 

“I told you I would, pup.” 

“Thank you, Daddy! Thank you, thank you, thank you!” Stiles practically launches himself at Derek. Kate scowls. Derek is right, she only served to push Stiles closer to Derek and destroy any chance of him being an ally to her. 

Derek cuddles the boy for a while before announcing that it’s lunchtime. He plucks Kate back out of the carrier. One hand cups the crotch of her diaper, feeling the heavy sogginess, but he doesn’t say a word. 

X 

Derek is pleasantly surprised to find how much he enjoys feeding Kate her bottle. He’d thought even holding her might disgust him, but it’s impossible not to be satisfied at the sight of her in her mittens and onesie, grudgingly swallowing down formula. 

Even though she has the incontinence shot he still mixes a little something extra into the bottle to ensure her bowels move. After the bottle is empty and he’s burped her he sits with her on the couch, listening to her tummy gurgling as the medicine takes hold. He knows the instant she fills her diaper but feigns obliviousness, smiling down at Stiles playing with his mermaids. Stiles is still a little fragile after this morning’s trauma and he’d wanted a pacifier. He looks absolutely perfect, sitting there in his onesie with his pacifier in, sweet and content. Exactly as Kate will eventually be. 

This time Kate only holds out for about five minutes before she starts to fuss. He’d like her to cry properly, a nice shrill wail like a real baby, but he knows that will take time. “Did someone go potty in their diaper?” he coos down at her. “Good girl, Katie!” He leans down to lift up Stiles so both his little ones are in his arms. “Stiles, would you like to be Daddy’s helper in getting Kate all clean?” 

Stiles looks a little dubious, but he nods. Derek can see him giving Kate a narrowed-eye look as he tries to wriggle against Derek’s shoulder as far away from her as he can get. He spits out his pacifier to ask: “Can we get a new baby sister, Daddy?” 

“No, pup. She’s ours now forever.” Derek smiles down at both his little babies. Kate is still crying, venting all her frustration with what’s clearly ramping up into a scream. “But hm, she’s pretty loud, isn’t she? Why don’t you give her your pacifier?” Stiles obediently pushes his pacifier into Kate’s mouth. She tries to resist so Derek helps, getting her mouth open and strapping the pacifier around her head once it’s in. Kate chokes around it but she has to adap and within moments he can hear her sucking away. “There! Now we’re going to give her a bath so she’s all ready for the party tonight.” 

That catches both of their attention. “Party?” Stiles asks eagerly. 

“That’s right! Our friends want to come meet Kate.” He tickles Kate under the chin. “Lots and lots of werewolves will be here saying hello, isn’t that nice? But first we need to get all clean.” 

“Can I have a bath too?” 

“Of course you can! Since Kate’s never had a bath before you can have your bath first, to show her what to do so Kate won’t be scared.” Derek ducks into the bathroom and puts them down on the floor so he can put water in the tub. 

As it fills up he undresses Kate, grabbing wipes to clean her up. Rather than put her in a fresh diaper he just leaves her lying naked except for the binding around her breasts on a towel on the floor. Stiles likes lots of bubbles so he pours in some bubble bath before helping Stiles undress and putting him in the tub. “Let’s show Katie how we sing the rub-a-dub-dub song,” he says as he puts soap on the washcloth. 

He knows Kate is watching in dread as Derek washes Stiles all over, spending plenty of time on his privates. He unplugs the tub when he’s done and lifts the slippery boy out, wrapping him quickly in a towel so he won’t be cold. When the scent of fresh urine hits his nose he almost thinks it’s too good to be true, but sure enough, Kate had gone again, this time soaking the towel. Stiles sees the wet spot and wrinkles his nose. “Daddy, she’s yucky.” 

“I know, she’s so little that she can’t control her tinkles.” Derek ignores the wet spot for now and takes off the pacifier before finally unwrapping the binding around Kate’s breasts. “Remember how yesterday we talked about the difference between Kate’ yum-yum and your pee-pee? She’s different here, too! Girls have nipples like you, but there’s are bigger and more sensitive, so they’re fun to play with.” He gives one a twist. It’s so sensitive from the binding that Kate squeals instinctively and rears up. 

Stiles is fascinated, reaching out so he can squeeze too. He freezes at the last minute and looks at Derek for permission. “Can I touch?” 

“You can play with Katie any time you want, since she’s your sister.” Derek helps him twist until the little nubs are nice and hard. “When girls grow up and become mommies, milk comes out of their nipples and babies can drink it.” 

Stiles looks incredulous. “Out of _there?”_

“That’s right!” 

“I think…I think maybe I remember that from before. But isn’t it yucky?” 

“No, babies like it a lot. Why don’t you try? Suck like it’s a pacifier.” 

Stiles hesitantly closes his lips around Kate’s nipple and starts to suck. Derek knows he likes to worry his pacifiers with his teeth and smiles when he hears Kate’s desperate moan of pleasure and pain. For his part Stiles makes a pleased sound, sucking for so long that Derek eventually pulls him away. “No milk,” Stiles says regretfully. 

“No, no milk from Katie. But that would be nice if there was, wouldn’t it? Then you could have a snack anytime you wanted.” Derek makes a note to look into it as he finally lifts Kate and puts her into the baby bath, filling it up with lukewarm water. He washes her quickly, saving her privates for last. Stiles “helps” by holding her still so she won’t thrash around. “All girls have yum-yums?” he asks as Derek parts Kate’s legs. 

“That’s right.” 

“Even Allison?” 

“Even Allison.” Derek swears Kate winces at the name. He can’t wait for Kate to see Allison tonight. He doesn’t bother to cover Kate’s eyes with his hands when he washes her hair like he does for Stiles, just pours it over her head and lifts her out. He’s not a cruel Daddy, of course, so he blots her eyes with a fresh towel before swaddling her and taking her and Stiles to her nursery. He lets Katie lie in her crib while he takes care of Stiles, getting him dressed in a party clothes and taking him to the office to wait in his playpen. 

Then he returns to the nursery and gets Kate a fresh diaper and binding, sprinkling on plenty of baby powder. When the diaper is on his gives it a kiss, knowing his girl is so sensitive to touch down there that even that might get her going. After she’s all clean he gets out a lovely pink dress picked out by Erica and Boyd. He puts on her mittens and booties, smiling at the pretty picture she makes. “Are you excited for our party tonight?” he baby-talks to her. “Everyone is so excited to meet you!” 

She sullenly turns her head away. Derek just chuckles and lifts her. There are two _very_ special guests tonight. Peter, who Kate probably thinks is dead, and Allison. He imagines Kate probably knows her niece is missing, but he doubts she suspects sweet little Allison will come through the door in her Daddy’s arms. 

This is going to be fun.


	3. Chapter 3

**Notes for the Chapter:**

> Forced orgasm, forced use of sex toys, spanking.  
> Also a note that Allison is far more regressed here than she is in the main universe

Kate is going to panic. The house is filling up with werewolves and she’s so, so outnumbered. They could tear her to pieces without blinking but all they do is coo over her, transferring her from one person to another. Derek had strapped a pacifier in and she almost bites through it in desperation. 

When she ends up back in Derek’s arms she turns her head into his chest just to escape, even though she knows that’s so, so fucked up. Derek _awws_ at her, giving her little kisses all over her cheeks the way she’s seen him do to Stiles. “It’s okay, little girl, they’re our friends.” 

She hears the door open and close again and then Stiles, in the arms of someone named Boyd, lets out a delighted shout. “Uncle Peter! Come meet my sister!” 

Uncle Peter— _Peter?_ It can’t be. Kate has a single moment of freefalling terror as she’s passed yet again someone’s arms before she looks up and sees him: 

_Peter Hale_. 

The one member of the Hale family who had ever truly scared her. Her brother said he had been in a coma, and eventually he must have been taken off life support because when Chris went to check on him he was just…gone. 

But now he’s here, and whole, and smiling down at her with a cruel glint in his eyes. “What a sweet little girl,” he says. “Like a little doll. Donovan, what do you think?” 

There’s a boy with him, clinging to his hand and dressed childishly. Another captive human, though this one seems to be allowed to act a little older. The boy wrinkles his nose. “She looks _old_ , Daddy.” 

Peter smiles indulgently at him. “She does look old, my smart boy, but remember, she’s a little baby even younger than you. She doesn’t know how to _talk_ , or _smile_ , or give _kisses_ …” His voice is sing-song and he rocks Kate with each word. “But she’ll learn!” 

“I don’t like her,” Donovan says decisively. “She’s _dumb.”_

“No, we don’t say dumb, remember? We’ve talked about this. She’s not dumb.” Peter keeps smirking down at her, eyes shining as if he’s imagining all the terrible things he’d like to do to her. “But why the long face, princess? Everyone is here to say hello to you!” He slides a hand under her skirt and rubs the crotch of her diaper, hard. “Hm, not wet. Are you just bored? Would you like something to play with?” Much to her humiliation he pulls out a set of keys and jangles them above her. “Look how shiny!” 

Kate turns her head away, but everywhere she looks all she sees are werewolves, smiling at her, talking amongst each other, cuddling close other humans like her. She feels so alone and vulnerable and she finally lets herself just _scream_ , trying to get out whatever sound she can through her pacifier. “Oh _no_ ,” Peter croons. “Derek, I think someone wants Daddy.” 

“Oh, sweetie.” Derek takes her back, using a tissue to wipe her face. “Daddy has something to make you feel _much_ better, Katie. Look who’s here!” 

Kate doesn’t think anyone could be worse than Peter, but she follows Derek’s gaze to see two more werewolves walking into the room. It’s a young man and woman she doesn’t recognize, and there’s a human in a frilly dress in the man’s arms. He’s talking softly to her, smiling down at her adoringly. Kate feels her lips bare in disgust. 

“Let’s go say hi,” Derek says to her. “Scott! Kira! Come meet Kate.” 

The man looks up and smiles. Kate can hear him baby-talking to the human as he walks closer: “You can say hello to our new friend, can’t you sweetheart? That’s right, a nice new baby for you to play with, I know you’ve been wanting a little girl to play princesses with…” 

“Kate, this is your cousin,” Derek says softly. “This is Allison.” 

The girl turns her head to look at Kate. Her eyes are large and innocent, face a little narrow, skin pale as milk but coloring still dark. Kate’s vision swims. _Allison._

It can’t be. 

She remembers the last time she saw her niece. Allison had just been a kid. Kate had been talking to her, explaining that there were monsters in the world that needed to be destroyed, and Chris had grabbed her by the arm and yanked her up. _Enough, Kate. We’re not raising her that way._

_She needs to know,_ Kate had argued, and things had spiraled from there until Chris finally kicked Kate out of the house and told her not to come back _until you get over this sick obsession_. Her last sight of Allison had been the girl sitting still, watching Kate leave with her eyes wide. 

It’s been eight years or so since then, but it’s unmistakably her niece here in front of her, two fingers in her mouth, head nestled cozily against the werewolf holding her. She’s staring at Kate curiously. Kate can’t tell if she recognizes her at all. 

“And this is your uncle Scott,” Derek continues. “He’s Allison’s daddy. And Aunt Kira. She’s Allison’s mommy.” 

How did they get Allison? Are Chris and Victoria dead? Kate has never cared about them much but the idea that these _creatures_ have her family— and, oh, God, Allison is the last of the Argents. She was supposed to carry on the name; carry on the _legacy_. She can’t be trapped here like this. 

“Can you say hi?” Scott says gently to Allison, smoothing her hair back from her face. “Say hi to your new baby cousin?” 

Allison’s brow furrows slightly as she stares at Kate. Now Kate is almost sure there’s a flicker of recognition in her eyes, but after a moment she smiles shyly and whispers, “Hi.” 

“Katie’s too little to say hi back,” Derek tells Allison, raising one of Kate’s mitten-trapped hands and flopping in back and forth in a wave. “But I’m sure she’s _very_ excited to meet you!” 

Allison smiles bashfully again and then hides her face in Scott’s shoulder. Kate wants to scream again but instead, to her horror, tears prick her eyes. She tries to blink them back but Derek has already seen. “Shh,” he croons, rocking her gently. “Daddy’s here.” 

Kate doesn’t want everyone else to see her crying, so she turns her face back into Derek’s chest. He shifts her for a moment, putting something between her and his shirt. A spit-up cloth, she realizes. So she doesn’t get his shirt wet when she cries. 

Derek doesn’t force her to move her head, but he does carry her around the room, constantly coaxing her to “come out and say hi!” Kate can feel lots of people touching her, wiggling her feet playfully or stroking their hands over her hair, telling Derek what a pretty little girl he has, cooing to their human captives that they’ll have so much fun playing with Kate when she’s a little bigger. Kate can’t fall asleep with this much noise so she just keeps her face hidden until she hears people starting to leave. Several people lean in to kiss her cheek. 

“Ally, can you say bye-bye to your new cousin?” she hears Scott ask. Derek nudges Kate to look up and she does so reluctantly, needing one more glance of her niece to convince herself that it’s really her. 

Allison is mid-yawn, cheeks flushed pink and eyes twinkling as if she’s just stopped giggling. She can’t possibly be _happy_ , can she? She’s an Argent. She can’t be brainwashed too. 

“Bye-bye!” Allison chirps, barely looking at Kate. She stretches around and reaches for Kira. “Mommy, up!” 

Kira takes her, tickling her until she squeals and kicks her legs. “See you tomorrow, Derek,” Kira calls as she heads towards the door with Allison in her arms. 

Someone else passes Stiles back over to Derek and Derek shifts Kate around so he can hold them both. Stiles yells a goodbye to the last few people leaving, then snuggles in against Derek, thumb slipping into his mouth. Derek smiles down at them and kisses each of their foreheads in turn. “My little babies,” he says lovingly. “Daddy loves his little babies.” 

Kate closes her eyes and keeps them shut for a long time, until Derek has dressed her in pajamas and put her into the bassinet. Allison’s face keeps dancing behind her eyelids, making it very, very difficult to fall asleep. 

X 

The next morning Kate wakes up to cramps in her stomach and within minutes she’s filling her diaper. It’s disgusting and awful and this time she can’t force herself to keep quiet out of pride. She wails, letting out sobs from deep in her chest, and Derek quickly scoops her out of the bassinet. 

“It’s okay, little girl, Daddy will make you all nice and clean.” 

He’s as good as his word, cleaning her up quickly and dressing her in a new onesie. Stiles is awake by then and Derek takes them both downstairs for breakfast, once again giving Kate nothing but a bottle. After breakfast Kate goes back into the bouncer, with the TV turned on to some kind of children’s show. She realizes quickly that this must be a special channel only shown here— the cartoon she’s watching is all about how special “adopted” babies are to their mommies and daddies and how important it is to be a good baby so you get lots of toys and hugs and kisses. 

She hates it, and hates the rattles Derek has left for her, and shuts her eyes until she can feel herself dozing off. The almost-sleep is interrupted after about an hour by Derek, who lifts her out of the bouncer without warning. “You weren’t sleeping _again,_ were you?” he coos. “I don’t know if it’s healthy for a little girl to sleep so much. Daddy might have to figure out a way to fix that.” 

_No,_ she needs to be able to sleep, she has to escape somehow. She almost whimpers but she’s gotten a shred of pride back, so she stays silent as Derek feeds her another bottle, burps her, and puts her down on a playmat with toys dangling down at her. Derek spends some time playing with Stiles— he has his own playpen filled to the brim with toys and Kate can hear him squealing excitedly as Derek plays with him. 

The rest of the day follows the same routine— toys, bottles, soft words from Derek. She tries to fall asleep a few more times but Derek keeps waking her up. 

After dinner she uses her diaper and cries for Derek again, hating herself all the while. He comes over quickly and takes her upstairs to the changing table. “Daddy had a good idea of how to get you on the right sleep schedule,” he tells her cheerfully as he wipes her clean. “Stay right there, sweetheart.” 

As if she could move, restrained to the table as she is. Derek disappears and comes back a moment later with something small in his hand. Her eyes widen when she realizes it’s a bullet vibrator. “Daddy got this special for you, my little princess,” Derek tells her as he puts in batteries. He pulls a bottle of lube out from the drawer of the changing table and slicks up the vibrator. “Let’s get this inside your yum-yum.” 

Kate’s vision blurs as Derek gently pushes the toy inside of her. She faintly remembers back when she was grooming Derek, how she’d taught him how to fuck her with vibrators and dildos, taunting him that they could always please her when he couldn’t. She can tell by the tiny smirk on his face that he remembers too— remembers how she’d fucked herself with the toys while he sat there, waiting to be given another order; remembers how she’d called him _my favorite little sex toy_ after she finally let him pleasure her himself… 

“There!” Derek says cheerfully once the vibrator is inside. He pulls a little remote out of his pocket and moments later she feels it buzzing. It’s so strong that she moans immediately, arching her back as it buzzes away. He lets it run for a few minutes, watching her as she writhes. It’s small enough that she can’t get off without friction, so it just brings her right to the edge almost instantly, keeping her trapped there. “Perfect!” Derek proclaims. 

He shuts it off, tapes a new diaper on, and gets out pajamas. She can feel it inside of her as he carries her over to the playpen downstairs, gets Stiles, and takes them both upstairs to the rocking chair in the nursery. “Let’s all read a story together,” he says. “Stiles, why don’t you pick out your favorite story SO Kate can hear it?” 

Stiles eagerly chooses something and Derek snuggles with them in the rocking chair. “Once upon a time,” he reads. “There was a little bunny named Ollie who lived with his daddy wolf in the woods…” 

After the story Kate is strapped into her bassinet. Even though today had been largely uneventful she’s so, so exhausted and eager for sleep. She closes her eyes— and what feels like moments later, is jolted awake by the vibrator, so strong and sudden that she moans involuntarily. 

It’s pitch-black in the room; she was probably out for an hour or so. The stupid thing must be on a _timer_. Derek is going to use it to wake her up every few hours, just like a newborn’s sleep schedule. 

The bedside light switches on and Derek gets out of bed to come tend to her. “Sh,” he murmurs as he lifts her out. “It’s all right, Daddy’s here.” He slips his hand into her diaper and finds the vibrator, rubbing it against her sensitive clit. “There we go. That’s it, good girl.” He smiles down at her as she comes. “That’s much better, isn’t it?” 

He rocks her for a few more minutes before putting her back in the bassinet. She notes dimly that he doesn’t bother strap her down this time. 

The vibrator wakes her up three more times that night. Each time she’s so surprised by it jolting her awake that she can’t help but moan, and even after Derek wakes up and gets her she whimpers and pants until he finally brings her to orgasm. He’s slow about it after that first time, letting it go on for almost an hour sometime in the early morning, all while whispering what a _fussy_ little princess she is. The vibrator also stimulates her bladder, so she wets her diaper twice and Derek has to change her. When morning comes he looks tired, but triumphant. “You sure know how to keep Daddy awake, don’t you?” he coos as she finishes the last orgasm. “And I bet it will be a _while_ before you’re on a real sleep schedule.” 

Today there’s no playmat or toys. She’s placed inside a bassinet in what must be Derek’s office and left to lie there until the vibrator goes off. She can hear Derek patiently explaining to Stiles that this is just how little babies act, needing to sleep in their bassinets during the day and crying for Daddy whenever they need help. At one point Stiles “helps” her feel better— Derek guides his hand to play with the vibrator, telling him it’s a “special pacifier for Kate’s yum-yum.” He must remember how sensitive she is to touch; she swears the vibrator gets stronger each time it goes off. 

She wonders if this is what happens to all the humans here, or if she’s just a special case. Maybe this is how they treated Allison. Maybe that’s how the brainwashed her. Kate is filled with anger and disgust every time she thinks about her niece, but with nothing else to occupy her mind she keeps going back to it. 

If Allison really is brainwashed like that…Kate will have to kill her along with all the other humans and werewolves here. She’s just too much of a liability otherwise. If— _when_ But she has to know if Allison is just faking. She has to find a way to see her again. 

X 

After another interminable two days of two-hour naps and orgasms, Kate is placed with Stiles into the stroller downstairs and rolled out the door. “Now, you need to be good for your babysitter,” Derek tells them as he maneuvers them outside. “And play nicely with your cousin, no fighting or fussiness.” 

Kate’s heart leaps. _Cousin_. That’s what they called Allison at the party. This is her chance. 

Derek takes them across the street to another house and knocks. The door opens to reveal Peter, smiling placidly, Donovan peering out from behind him. “Here’s my favorite nephew!” he cheers, lifting Stiles out of the stroller. His gaze flickers to her. “And Kate.” 

Derek lifts her out of the stroller. “Daddy will be back very soon,” he promises her. “Be a good girl for Uncle Peter and I’ll give you a present when I’m back, all right?” He gives her four of those loud _mwah mwah mwah_ kisses and hands her over to Peter before kissing Stiles too and heading out the door. Kate finds herself wanting to call out after him. She’s afraid to be left with Peter, who stares down at her like he wants to hurt her. At least Derek isn’t going to actually _kill_ her anytime soon. 

And God, what if the vibrator goes off? Or she uses her diaper? The idea of him taking care of it makes her feel physically ill. 

“Let’s get you on your fun mat,” Peter baby-talks, putting her down on a crinkly playmat. There are cartoon wolves on the arches, grinning at her with their sharp teeth. She can hear Stiles and Donovan playing together, squabbling over a toy. 

Peter tries to get her to play with the little plush toys dangling from the mat, but she does her best to ignore him. About twenty minutes after Derek leaves the phone rings and Peter leaves the room to get it. 

She has no time to enjoy the privacy; Stiles and Donovan crawl over to her immediately. “Your sister is dumb,” Donovan tells Stiles, poking at Kate with his finger. 

“Nuh-uh,” Stiles says defensively. “She’s just little, Daddy said so. She’ll be more fun when she’s bigger.” 

“I used to have a baby sister. Now she’s Johnny’s baby sister. She was dumb too.” Donovan reaches out to poke at her chest. It’s still bound up, sensitive under the binding. “Little sisters are all squishy here,” he tells Stiles knowledgably. 

“Boys, don’t pester the baby,” Peter says as he walks back in. 

“We’re just playing, Daddy.” Donovan is still poking her. 

“It’s not nice to poke, Donovan. Give your cousin a kiss to say sorry.” 

Donovan sighs hugely but leans over to plant a wet kiss on her forehead. Kate thinks she hates this boy more than even Stiles and she wishes desperately she could hit him. Then, as his face looms over hers, she realizes she can do one thing. She purses her lips and spits in his face. 

Donovan rears back, disgusted. “Ew! She spitted at me!” 

Kate is enormously pleased with herself, even though she’s a little annoyed it’s taken her this long to recognize a weapon still in her arsenal. Peter clucks and comes over “Look at that little smirk,” he says quietly. “I think little Kate has to learn it’s not nice to spit.” 

“Maybe she didn’t mean it,” Stiles says, voice a little quivery. It’s like he’s defending her— but Kate doesn’t need or want his help. She moves her head as best she can and spits at him too. 

“Okay, that’s enough of that.” Peter lifts her quickly, not bothering to support her neck. “Bad little girls have to be taught a lesson. Donovan, Stiles, stay here. Play with your toys. That means _you_ , Stiles, I don’t want you upset.” 

“Okay,” Stiles says in a small voice. 

Peter carries her out of the room and into what must be his bedroom. “Your Daddy doesn’t believe in spanking Stiles,” he tells Kate. “And that means he probably won’t ever spank you, either. But when you’re in my house, you’re under my rules.” He takes off her onesie completely and strips off her diaper. “Ten spanks seems like the right number to make sure you learn never to do that again.” 

She tries to brace herself but the first slap still comes hard and painful. She can’t stop herself from crying out. “Oh, I’m sorry,” Peter practically purrs. “Does that _burn,_ Kate?” 

The next nine come in quick succession, hot and stinging and _awful_. If she had a voice, she would be begging him to stop, but as it is all she can do is cry. Each spank jostles the vibrator, but soon she even forgets that with the pain. 

“All finished!” Peter says brightly when he’s done. He puts her diaper back on, even though it hurts like hell to have anything touching her bottom. “If you spit at your cousin or brother again, I’ll have to give you _twenty_ spanks. So let’s be good as gold, hm?” 

He doesn’t bother to wipe off her face like Derek would, just carries her back into the living room and cuddles her on the couch as he watches Stiles and Donovan play. She lets herself cry for a while at the pain and horror of this situation. Peter fetches a bottle and feeds it to her, crooning to her that she has to drink it all to be a big strong girl. 

She’s completely wrung out by the time Derek returns. He swings up Stiles in a big hug, then gives a comically huge frown when he sees Kate’s face. “Uh-oh. What happened?” 

“Someone didn’t know how to behave and earned herself a spanking.” Peter transfers her into Derek’s arms. “Ten spanks for spitting, but she’s been very well-behaved since then. I think it’s just the right punishment for her from here on.” 

“Of course you do,” Derek mutters. “Thanks for watching them, Peter. Say bye-bye to Donovan, Stiles.” 

Stiles chirrups a bye-bye. Kate hides her face in Derek’s shirt, unable to stop herself from feeling relieved when he doesn’t put her in the stroller but just carried her back across the street. He puts Stiles into his playpen and carries Kate upstairs. 

“I bet it wasn’t nice to get spanked,” he says gently after sitting with her in the rocking chair. “Daddy won’t ever spank you, but your aunts and uncles will spank you when you misbehave during playdates. You should learn how to behave, shouldn’t you?” 

Kate barely hears the second part; she’s so relieved at the idea that Derek won’t spank her. She finds herself relaxing against him, but before she can recoil the vibrator stats to buzz. She whines, afraid Derek will make her wait before he helps her come. 

“Here you go, my sweet girl,” Derek coos, reaching into her diaper to grab hold of the vibrator. He gets her off quickly and almost kindly, for once not getting her to the edge and then backing off. She’s lost in a hazy post-orgasm blur and for a moment it’s like she _forgets_ what a monster he is— all she knows is that he isn’t Peter, and he’s not about to hurt her, and he just helped her feel _so_ good. She smiles dreamily up at him. 

“Did you smile at Daddy?” Derek says delightedly. “Your first smile!” He tickles her belly and she writhes away, remembering herself. _Stupid!_

Even so, she doesn’t fight when he cuddles her and kisses her cheeks. He may be a monster, but he isn’t Peter. Right now, that’s all that matters.


	4. Chapter 4

**Notes for the Chapter:**

> Sincerest apologies for the wait! To make it up to you, the darkest chapter yet. This is officially the place where all the dark prompts go, ladies and gentlemen. This chapter featuring:  
> Forced cum drinking  
> Forced breastfeeding  
> Non-con body mod and threats of more mods
> 
> Thanks to keldjinfae for coming up with some wonderful prompts!  
> Anything else you want to see in this story, prompt away!

Over the next few days, Kate finds herself wishing that Derek would forget himself for a moment and talk to her like an adult. She doesn’t care if it would just be spewing hate, so long as it’s not in that high-pitched adoring coo. 

And he never leaves her alone. Practically every second he’s there, ticking her belly, using her hands to bat at the buttons on her infant-style toys, moving her legs back and forth to pretend she’s “running.” People keeps stopping to by to “visit the new baby,” so Kate is constantly being prodded and cuddled. 

Really, it’s no surprise when she finally snaps. 

After she’d broken Stiles’ stupid toy Derek is careful about leaving them alone together. During the day she usually has to lie in a bassinet staring at a mobile of little lambs while Stiles plays in a giant playpen and Derek works on his computer. After both Kate and Stiles are put down for a midafternoon nap, however, they’re left to play in the living room, with Kate on the idiotic mat and Stiles playing with whatever he dredges out of his giant toy box. Derek usually sits with them, but he leaves the room every so often to grab a bottle or do a quick chore. 

Stiles usually ignores her, remembering what she did when he gave her the mermaid, but after about a week he crawls over to her hesitantly and gently pets her hair. Derek, curled up on the couch with a book, makes a noise of approval. “Do you want to play with your little sister, Stiles?” 

“Uh-huh.” Stiles looks down at the stuffed animal he’s carried over. “Does she like toys?” 

“Of course she does, everyone likes toys. She’s just too little to play with your big-boy toys. But you can still have fun with her. Here, let me help you. You can hold her, if you promise to be gentle.” Derek bends down next to them and pulls Kate up until her head is in Stiles’ lap. “Here, look what happens if you do this.” He presses Stiles’ finger into Kate’s palm and she grips it. Derek loves showing off this little trick and Kate can’t figure out how the hell to stop herself from doing it. 

Stiles looks fascinated and repeats it with her other hand. “Why does she do that?” 

“Because she loves you. Isn’t that right, Katie? Don’t you love your big brother?” 

Kate rolls her eyes and Stiles looks hurt for a moment. There’s a faint ringing— Derek’s cell phone, which must be upstairs in his office. Derek presses a quick kiss to Stiles’ forehead. “I’ll be right back. Be very careful with her, please.” 

Stiles takes one finger away so he can pet her hair again, but keeps his other finger clutched in her fist. Kate immediately focuses all her energy on her hand, gripping his finger as tightly as she can. If she can make her hand move, maybe she can snap his finger. That’s a wonderful way to cause pain, a nice searing, breathless moment of agony for the victim. That’ll teach this little shit she isn’t his “sister.” She doesn’t even care what her punishment will be, making Stiles cry will be worth it. 

Stiles screws up his face in pain as she holds on. “Oww,” he says, trying to pry her fist open. “ _Stop_ , Katie. That _hurts_.” He gives a powerful tug and wrenches his finger away. _Damn it_. 

Derek walks back into the room and frowns at what he sees. “Stiles? What’s wrong?” 

Stiles looks at him piteously. “Kate hurt my finger.” 

“Let me see.” Derek holds it carefully, probably taking the minimal pain before he gives it a quick kiss. “There. All better. She doesn’t know her own strength, pumpkin.” It’s clear, though, from the dark look he gives Kate that he knows it wasn’t an accident. 

Much to her surprise she isn’t punished for the rest of the day. It gives her hope that maybe Derek is easing up on her, letting his guard down. She goes to bed feeling almost satisfied. 

The button vibrator Derek is still keeping in her diaper goes off sometime in the early morning, jolting her awake. Derek quickly gets out of bed and helps her get off, cooing down at her when he legs stiffen. “It’s time for your feeding too, isn’t it?” 

She drifts off a little as he carries her downstairs, but his soft voice keeps her awake as he starts to prepare a bottle. “You weren’t very well behaved today, little lady. I know what you tried to do to your brother. That will never, ever be okay.” 

Kate feels a tiny frisson of fear. Of course. He’s still going to punish her. He just wanted to wait until Stiles was asleep, so it wouldn’t upset him. 

“But it isn’t your fault. Little babies like you get out-of-sorts sometimes and lash out, I understand that. The problem is usually something with your diet. I realized today you’re probably not getting enough protein with your formula, and that must be making you feel all tired and cranky. So you get a _special_ bottle this morning with _lots_ of protein.” 

He puts her into the high chair, ignoring how her head lolls, unsupported by her neck. As she watches Derek prepares a bottle of formula, only filling it up three-quarters full, then reaches down to unbutton his boxers. Kate catches her breath as his dick slips free. 

When they were together she used to make fun of it. Tell him how small he was in that taunting way that boys couldn’t get enough of from older women. There’s nothing small about him now as he languidly strokes himself, fingers squeezing the head of his cock gently. Once he’s hard he takes the bottle and begins to jerk himself off into it. 

He comes quickly, with a muffled moan, filling the bottle up the rest of the way. As she watches he twists on the cap, then shakes it up. “Here you go,” he sings, lifting her out of the high chair. “Yummy-yummy. Open wide.” 

Kate clamps her lips shut but Derek works to nipple into her mouth, smiling tolerantly all the while as if he didn’t expect anything else. Once it’s in her mouth she holds completely still, forcing herself not to suck. 

Derek tsks. “It’s getting into your tummy one way or another, little girl.” He rummages with one hand through a drawer— Kate notes sourly that they’ve all been child-proofed— and pulls out what she quickly realizes is a ring gag. “Using this won’t be any fun for you. Drink it all up now while it’s still nice and warm, Katie-cat.” He pushes it further into her mouth until she can barely breathe. 

There’s no way out. She drinks, trying hard not to let any tears fall. She can taste him, something she hasn’t tasted for a long time. She used to brush her teeth for five minutes after sucking him off, disgusted to think she’d had him in her mouth. 

Derek praises her the whole time. “You liked that, didn’t you?” he coos once the bottle is empty. “Now that you’ve had lots of protein you’ll be much less fussy. We’ll have to make sure you get a special bottle every time you act up.” He kisses her forehead and carries her back upstairs. 

It takes her a long, long time to fall back asleep. The satisfaction is gone. 

X 

The next morning Derek dresses her in an awful onesie with fur and a little hood that flops over her eyes, complete with ears and googly eyes. “Little wolf pup!” he coos, putting mittens on her hands that look like paws. “Do you know what we’re doing today, pretty girl? It will be such a big day for you!” 

Kate glares up at him and Derek clucks, flicking her nose playfully. “I know, I know, you’re so fussy in the morning. But Daddy wants to see that nice big smile again today. We’re going to take family pictures, and then go to the doctor’s for a little checkup. Won’t that be fun, Katie?” 

Both of those ideas fill her with equal parts horror and fury. Derek picks her up and carries her downstairs, where he straps her into the car seat she’d come here in. Stiles is dresses in a onesie similar to hers and he’s in his usual bubbly mood, shouting at Derek to listen to his growl. Derek laughs at him and picks him up for a kiss before he carries both of them out to the car. 

Kate stares out the window as they drive, trying to get a sense of her surroundings, but she sees absolutely nothing remarkable. Derek is playing a CD, which Stiles is loving: “ _The wheels on the bus go round and round…_ ” 

“Daddy, do I need shots today at the doctor?” Stiles asks about five minutes into the drive. 

“No, pumpkin. Only Kate needs to be looked at by Dr. Deaton today.” 

“Does Kate need shots?” 

“Oh, yes. Katie needs lots of shots to keep her healthy, since she’s so little.” 

Stiles nods, satisfied with this answer, and beams at Kate. “Daddy takes the pain from the shots so there’s not even an owie,” he tells her knowledgeably. 

What the hell shots is she going to get today? Kate wriggles uncomfortably in her scratchy onesie, feeling more anxious by the second as Derek turns into a parking lot. 

He gets them both out of their car seats and easily carries them across the lot. Kate whimpers, already fed up with whatever this bullshit is, and Derek kisses her forehead soothingly. “Be a good girl, now,” he tells her, a hint of warning in his tone. There are pictures in the window, people posed in elaborate, childish outfits, holding rattles and stuffed animals. Kate sees to her horror that there’s one of Allison, being held by those people who’d had her at the party. 

They’re not going to take _her_ picture and put it up there, are they? No. She can’t bear the thought of everyone being able to see her like this. 

A man meets them at the door, beaming. “Here’s the Hale pack! I’ve got it all set up for you, Derek. Come on in.” 

There’s a set arranged for them, a blue sky and a bunch of greenery designed to look like a forest. Derek sits on the ground, arranging Kate in his lap. He wedges a pacifier into her mouth while the man fusses with Stiles, getting him to curl up beside Derek, head on Derek’s knee. Flashes start going off. “Great!” The man shouts. “These are adorable, Derek. Let’s get a couple of the baby on her own.” 

Derek props Kate up against a little stool. “Can you smile for the nice man, sweet pea? Or should we keep your pacifier in?” 

Kate glares at him and Derek just chuckles. “Okay, my fierce little pup. Pacifier it is.” 

Kate tries to turn her glare in the direction of the camera, but the lights flash without warning, blinding her. All of a sudden it’s like everything gets turned up ten degrees, light and sound and feeling, and she finds tears in her eyes. She tries sluggishly to move and Derek rushes forward, wrapping her fingers around a rattle. “There’s a toy for you, sweetheart!” 

Her hand won’t let go of it no matter how hard she tries. The flashes keep on coming and tears stream down her face. She can hear Derek _aww_ ing at her, and when the flashes finally stop he gently wipes her nose with a handkerchief. “Cutie-pie,” he coos. “Now let’s get some pictures with you and your brother.” 

Stiles immediately and enthusiastically grips her in a tight hug. Kate grits her teeth, trying to keep any more tears at bay. Derek keeps adding stuffed animals and toys as props, then steps back into frame so he can hold Kate standing up while Stiles clings to him around his waist. 

It feels like it goes on forever, and eventually Kate can’t take it anymore and buries her face in Derek’s shoulder. When they’ve finally had enough of that pose they only make it worse— Kate is undressed cheerfully by Derek, so the man can take pictures of her “cute little bottom,” and then she’s posed with noting on but a feathery, sequined headband, next to wooden blocks spelling out “Baby Hale.” 

“ _Very_ photogenic family,” the cameraman says approvingly, dimming the lights after an eternity. “I think you have some real winners here. Get her dressed and come take a look.” 

Kate tunes out while Derek looks at the pictures. She lets herself dream of the hunters coming and destroying this whole town— though she can’t even imagine how embarrassing it would be if they found her like this. No, she has to find a way out of this herself. Somehow she has to get her legs working… 

“Thanks again, George!” Derek says cheerfully, scooping up Stiles with his other hand so he can carry both of them out to the car. Stiles is beaming as always, completely immune to the humiliation. 

“That was fast!” Derek says after he has both of them buckled into the car seats. “We still have an hour before Kate’s appointment. “What should we do, sweetheart? Do you want to go to the park? Or the big playground?” 

Stiles knits his brow as if he isn’t sure how to make the decision. Derek smiles indulgently at him. “I have an idea. Remember how I told you my friend Eliza just had a new baby? Why don’t we visit him?” 

“Yes, Daddy!” Stiles swings his feet happily as Kate rolls her eyes. Great. Another human trapped like this. Just what she needs to see. 

The stupid songs go back on while they drive, but it doesn’t take long to get where they’re going. This time Derek gets the double stroller out of the trunk and straps Kate in. Stiles just gets to sit there without being restrained, the little brat. 

When Derek knocks on the door it’s opened to reveal a woman holding— Kate’s eyes nearly pop out of her head. It’s a _real_ toddler. Maybe two or three years old. “Derek!” the woman says, sounding pleased. “You here to see Sam?” 

“Yeah, we were in the neighborhood. Is he up?” 

“He sure is. Come on in.” The woman beams down at Stiles and Kate. “Ooh, and here’s your new baby girl! I was so sad I couldn’t come to the party, but with Sam…” 

“No worries, I understand.” Derek waves at the toddler. “Hi, Max.” 

Max is staring down at the stroller with interest. “Peoples?” he says to his mother, sounding bewildered. 

“Those are babies, Maxie,” the woman says as she leads them into the house. “Remember how we talked about this? Humans may look like they’re grown-ups, but they’re actually babies even tinier than you. And the little girl is even younger than your new brother!” 

There’s another werewolf in the living room, holding an actual practically-newborn baby. Kate has never wanted to have control over her body as much as right now. There has always been something so _satisfying_ about killing a family with werewolf pups— knowing that she’s stamping out the evil before it can reach its horrifying potential. She hears herself make a soft, almost pathetic whimper of frustration and her head lolls uselessly as she tries with everything in her to get control of her muscles. 

Derek helps Stiles out of the stroller. “Kate’s being a little fussy,” he says softly to the boy. “Let’s leave her alone for a while, all right?” He carries Stiles over to where the baby is and Kate can hear them both gushing over it, Stiles with childish squeals. 

Meanwhile, Max toddles over to Kate, peering at her with interest. “Baby?” he says again, sounding a little worried, as if he can’t quite grasp the concept. 

“That’s right,” his mother confirms. “And she’s not like your brother, remember? She gets to be a baby forever and ever. This is how we keep our humans from growing up into bad, mean people like other humans are. See how she’s wearing mittens like Sammy wears? And she isn’t able to move or talk like real grown-ups? That’s _good_ , it means she can’t ever hurt anyone.” 

The toddler smiles and reaches into the stroller to clumsily pat Kate’s cheek. “Nice baby,” he says, sounding satisfied. 

After that she’s left alone for a while, as the toddler plays on the floor with a pacifier in and the others stay grouped around the baby. Stiles gets bored and crawls away to play with some of the toddler’s toys. _Idiot_. Kate tries again to move, but nothing works and she’s so, so _so fucking frustrated_. Whimpers keep slipping out, getting louder and louder until she hear the adults remarking in amused voices on her “temper tantrum.” 

Max comes back over to her, frowning. He tries to pat her cheek again and she tries to twist away from him. He takes out his pacifier. “Nice baby,” he says again before trying to stick his pacifier into her mouth. Kate tries to resist, but her mouth is so slack that she can’t. 

“Oh, Max, good job sharing!” the woman says, hurrying over to help him slide it in. 

“You know, she’s probably hungry,” Derek mutters, turning to search through the baby bag. “Stiles, here are some Cheerios for you, don’t make a mess, please. Katie…oh, damn it. I forgot to bring a bottle. Shit! I don’t think we have time to run back home.” 

Right on cue Kate hears her stomach grumble. She whimpers again around the pacifier, hoping Derek will let her have some Cheerios. She misses real food, and she swears she can still taste last night’s “special” bottle. 

“You want me to feed her?” the woman offers. “Unfortunately I don’t have any pre-pumped bottles right now, but if you think she’ll latch I’m happy to help out. I know it won’t have the same effect as the formula but at least it’ll keep her settled until you can get back home.” 

“I can’t make you do that.” 

“It’s no trouble. Honestly, since Sam isn’t ready for a feeding it would be a relief.” The woman reaches to unhook her bra, taking a seat on the couch. 

“Eliza, you’re a lifesaver.” Derek unstraps Kate from the stroller. She tries to communicate her horror with her eyes but he ignores it, laying a tender little kiss on her forehead. The woman pulls off her shirt, revealing her full breasts. “She’ll probably need some coaxing before she’ll latch.” 

Kate is placed into the woman’s arms, head propped up on a little pillow. The woman works the pacifier out of Kate’s mouth, replacing it almost immediately with her breast. Kate tries to bite down but the woman anticipated that and has one hand on Kate’s jaw, holding it open. “There you go, sweetheart,” she coos. “This will help that hungry tummy!” 

Kate is so used to sucking on pacifiers and bottles that she almost sucks on instinct, but she fights it off. They can’t make her do this. She won’t. She’ll stay here for as long as it takes, but she will _not_ breastfeed from this woman. Not after what Derek did last night. This is even worse than that because this woman is a stranger, and she’s not even doing it as a punishment. She’s just doing it because Kate’s nothing but a little baby to her. A little baby who needs to be fed. Kate won’t play along with that, not for anything. 

“She’s not cooperating,” the woman chuckles after a moment. 

“No, she’s not being very well-behaved today.” Derek’s voice is disapproving. “Maybe she needs to spend some time with her Uncle Peter.” 

The threat sends a sizzle of fear down to Kate’s stomach and she involuntarily sucks like she would on her pacifier for comfort. Immediately a stream of milk comes out, warm and sweet after the blandness of formula. 

“There we go!” the woman says cheerfully. “That’s a good girl. She just needed to get used to it.” 

After that first mistaken gulp it’s like Kate’s mouth just moves involuntarily, sucking and sucking until there’s milk running out the side of her mouth. The woman rubs an absentminded circle on her stomach and Kate can hear her remarking to Derek over how cute Kate looks in her wolf onesie. Finally the stream of milk slows and stops and Derek lifts Kate away, draping a burp cloth over his shoulder as he begins to pat Kate’s back. “Lifesaver,” he repeats. “I owe you one.” 

“No worries, I’m happy to help.” The woman puts her bra back on. “She was trying to get at me with her teeth, the little scamp.” 

“Those teeth are on thin ice. I see her looking at Stiles like she wants to bite him. The first time she tries, she’ll find herself in the dentist’s chair before she can blink.” Derek gives Kate a stern look, increasing the intensity of his pats until she burps and spits up a small amount of milk on the rag. 

She doesn’t even bother to try and fight as Derek straps her into the stroller. Right now, she doesn’t see anything to fight for. 

X 

Derek is in a good mood as he drives to the doctor’s office. Kate is sulking in the back and Stiles had tired himself out with the big morning, so he’s yawning and heavy-lidded by the time Derek pulls unto the parking lot. “Nap,” he demands sleepily as Derek comes to unbuckle him. 

“Not yet, sweetheart. Kate needs to see Dr. Deaton first.” 

Stiles pokes his lip out but doesn’t whine. Derek is pleased to see that he hasn’t been influenced by Kate’s bad behavior and makes a mental note to get him a special treat for being such a good boy. When he picks up Kate he notes with satisfaction that her diaper is full. 

After he checks in he sits Stiles down in a chair. Melissa spots them and comes out to say hello, so that should keep him occupied for a while. Stiles loves Melissa. Derek pulls one of the adult changing tables down from the walls. Kate’s eyes bulge when he realizes she’s about to be changed publically and an angry sound squeaks out. Derek tsks at her. “No fussing,” he warns. 

He takes his time changing her, making a big production about getting her powdered and re-diapered. “And now we tape up the sides just like that, and now the little girl gets a big kiss on her tummy, yes she does!’ He re-buttons her onesie, flopping the little hood back over her head so the felt ears are sticking up. By the time he’s finished Stiles needs a diaper change too so Derek gives Kate to Melissa to hold. Melissa tickles her, bouncing her up and down until Derek takes her back. “She’s prettier than I thought she’d be,” Melissa says approvingly. “Given her biological age.” 

“Ally’s prettier,” Stiles says with the casual, truthful cruelty of a child. Derek laughs. He’s been keeping Allison and Kate separated, wanting Kate to stew over knowing her niece is here, but maybe it’s time to arrange a playdate. 

Melissa leads them to an examination room where they can wait for Deaton. There are oversized cardboard books for the little ones to look at and Derek reads one to Stiles, largely ignoring Kate on his lap except to pat her back absentmindedly every few minutes. Stiles is still sleepy and after the book is over he nuzzles against Derek’s shoulder, yawning hugely. 

There’s a knock on the door and Deaton walks in. “Hello, Derek,” he says, eyes on his charts. “Hi, Stiles.” 

“Hi,” Stiles says in a tiny voice. He still gets a little wary around Deaton, the poor baby. Stiles presses even closer to Derek for comfort and pouts when he realizes Kate is in Derek’s lap, so he can’t climb there. 

“And here’s Miss Kate. Ah, you were right, her breasts are small enough that I don’t see any need for a reduction. How has she been acclimating?” 

“She has her good moments.” 

“Well, let’s figure out how to keep those coming.” Deaton pats the table so Derek will lay Kate down. “It looks like they gave her the full workup of shots, but I know you mentioned on the phone her acting up, so I think we can probably give her something to take care of that.” 

“What?” 

“Well, right now she has no control over her body, but she still has full cognitive capability. I can give her something that would…disorient her a bit. She would still who and where she was, but she would process things a little slower. It also targets the part of the brain that controls aggression, so she’ll be much calmer and less likely to try and hurt you or Stiles.” 

Derek looks down at Stiles, who’s still trying his best to fall asleep against Derek’s shoulder. “And it’s safe?” he says in a low voice, not wanting Stiles to hear. 

“It’s not used often, because some research indicates it might make it difficult to ever teach them to talk again. But I understand that you weren’t really planning on giving Kate the ability again, so it shouldn’t matter.” 

Derek takes his time deciding, mainly so he can look directly into Kate’s horrified eyes as he does so. He likes the idea of destroying her aggression. But he’s taken such pleasure in thinking of that bright, evil little mind trapped in a helpless body. “I don’t want to take away her awareness,” he says quietly. “I need her to still remember everything she’s done, so she understands why she’s here now.” 

“She will. She’ll just feel a bit…floaty and disconnected. If anything, it’ll only increase her frustration. Usually I wouldn’t recommend this for anyone who legitimately want a painless regression, but I think it’s useful for cases like these.” 

“Will she still be able to cry?” 

“Oh, absolutely. In fact she might be much more vocal— you’ll hear a lot of involuntary noises from her, like little babbles. She might have trouble making eye contact sometimes, since she’ll be a bit spacey.” Deaton shrugs. “It’s your call.” 

“Hmm.” Derek tilts his head as he considers Kate. She’d tried to hurt Stiles again yesterday. Derek can’t let that happen again. “Can it be undone?” 

“It needs to be renewed four weeks after the first shot, then every six months after that.” Deaton drops his voice, low enough that Kate can hear but the lightly dozing Stiles certainly can’t. “You need to take a firm hand, Derek. We talked about this with Stiles, and I still say you were too easy on him. She needs to learn that you’re in charge of _everything_ now.” His voice changes slightly as he coos down at Kate. “Isn’t that right, pet? Daddy’s in charge of _this…_ his hand lightly squeezes the crotch of her diaper— “and _this_ …” his hand moves up to the binding around her breasts— “and especially _this_!” He taps the side of her head. “Daddy can do whatever he likes to his little girl. The sooner she accepts that, the sooner she’ll be regressed.” 

Derek smiles and reaches out to tickle Kate’s foot. “Well, I certainly want to help my little girl regress! Let’s give it a try.” 

Kate’s eyes fill with tears and she makes an angry little sound. Deaton chuckles as he prepares the syringe. “Hold her nice and still, Derek.” 

Derek detaches Stiles from him gently and holds Kate down. “There we go,” he murmurs as Deaton depresses the plunger. “Good girl, Kate.” He pets her hair, watching with satisfaction as her eyes lose focus. “That’s much better, isn’t it?” 

Deaton places a Band-Aid with Minnie Mouse over the injection site. “There you go. All done. Anything else I can do for you today?” 

“Well, the shot might have taken care of it, but I’m thinking about having her teeth removed to make sure she can’t bite. I’d like your thoughts on it first.” 

“You can do that. Or you can just have them filed— the dentist does it very well, blunting them so if she does bite it wouldn’t hurt a bit. That way she can still chew a little or hold onto things with her teeth. I can have the front desk make you an appointment for next week if you like.” 

“That sounds great. Thanks, Alan. Any side effects of the shot I should look out for?” 

“None. Let’s schedule a check-up in one month, in case you decide to renew it.” Deaton brushes a strand of hair away from Kate’s forehead, smiling in satisfaction as her mouth falls open slightly and doesn’t close. “Very good, it’s already taking effect. She’ll be just fine.” 

Derek picks up Kate none too gently, then carefully wakes up Stiles. “We’re all finished here, sweetheart.” 

Stiles yawns and raises his arms so Derek can lift him with his free hand. “Did Kate get owies?” 

“Just one, isn’t she a lucky girl? The doctor says she’s perfectly healthy.” 

“None for me?” 

“No, my little prince. You’re absolutely perfect.” Derek can see the slightest frown creasing Kate’s forehead, as if she can’t understand what they’re saying. _Excellent._ “Now let’s go home.” 

X 

Stiles is very sleepy for the rest of the day because he didn’t have his naptime, but he forces himself not to fall asleep early. Because he’s bigger than Kate he has a later bedtime and he loves to have that time to spend alone with Daddy. 

Being a big brother is nice, but sometimes he misses the way it used to be. 

He plays on the floor with his blocks while Daddy puts Kate to bed. Meeting the tiny baby today had made him feel a little funny. He knows he’s not _really_ as little as Sam or Max— except he , at least in his mind. He tries not to think about it. 

Daddy doesn’t take very long with Kate, which is good, because Stiles is almost falling asleep on the carpet. “My sleepy boy,” Daddy murmurs, lifting him from the ground and cuddling him tenderly. “You have to stay awake for your bath, sweetheart.” 

“No,” Stiles whines. He just wants a story and lots of kisses and for Daddy to tuck him in with his blanket. 

“Shh, you need your bath. We’ll get out all your duckies, all right?” Daddy fills up the tub with water and gets out all the bath toys. Stiles perks up a little bit once he’s in the water. He likes that Kate’s too little to play with bath toys, but _he’s_ big enough. 

He sends his Iron Man ducky out to rescue his Thor ducky from the bad humans who captured him as Daddy washes his hair. As he plays, having Iron Man drown all the bad humans so they can’t hurt anyone else, he thinks about Kate and how naughty she is. “Is Kate going to be a bad human forever?” he asks Daddy. He doesn’t like living with a bad human. He’s supposed to be safe from them now that he’s here with Daddy. 

Daddy pauses for a moment before he pours another cup of water over Stiles’ head, hand firmly over his eyes so they won’t sting. “I don’t know, sweetheart. I think in her heart she might always be bad. But we’re making sure she can’t do any bad things, so it doesn’t matter. She’s like a gun without bullets now.” 

Stiles remembers guns from before, even though he isn’t allowed to play with any toy guns. Daddy said _no way_ when Stiles saw them in the toy store once. “What about me?” he whispers. “Is there badness in my heart too?” 

“Not a drop, my perfect boy. That’s why _you_ have more grown-up privileges, because I know you can be trusted with them. And you would never do bad things like Kate, would you? You make me so proud, every day.” Daddy pulls the plug out of the tub and wraps Stiles up in a towel. “You know I love you the most, right?” he whispers in Stiles’ ear. 

“Promise?” 

“Cross my heart.” Daddy blows a raspberry on his tummy, taking him by surprise and making him shriek. “How about you give your little sister a good-night kiss and then go beddy-byes?” 

“Okay, Daddy.” Stiles snuggles into Daddy’s shoulder as he’s carried into Daddy’s room. He feels better, it’s nice to be reminded that Daddy loves him best. 

Kate is asleep in her bassinet. Her feet in sleep socks are tied to the sides and there’s a strap going across her chest. Stiles wonders why, since she can’t move on her own anyway. Maybe they just make Daddy feel better. Stiles would want the straps there if _he _had to sleep in the same room as a bad human.__

 _ _Daddy bends Stiles over the bassinet so he can kiss Kate’s cheek. Kate is sleeping so soundly that she doesn’t react at all. “Night-night,” Stiles whispers to her before yawning and resting against Daddy’s shoulder again.__

 _ _

“Okay, sweetheart,” Daddy says once they’re back in the nursery. “I think you’re too sleepy for a story tonight. But do you have any more questions for me about Katie? I don’t want you to ever feel uncomfortable or afraid around her. She won’t ever hurt you. I won’t ever let her. “ 

“Wh-what if she tries?” Stiles remembers how Kate hurt his mermaid. What if one day Daddy leaves the room, or gets stuck somewhere, and Kate does something really _really_ bad? 

“She can’t right now. The doctor gave her a special shot today so she can’t do a single thing without me, isn’t that nice? But if she _does_ try in the future, she’ll be in big trouble. She’s our little girl now, but there are a lot of nice werewolves who would be happy to take her for a little while. Uncle Peter’s said a hundred times that if I don’t want her here anymore she can go live with him. And remember Deucalion? He’s been thinking about adopting a human of his own, and he asked if I’d be willing to part with Kate someday. They wouldn’t be nearly as nice to her as we are! That would teach her not to try and hurt my special boy.” 

Stiles’ eyes are wide; he didn’t know babies could go to other families just like that! “She might not be my sister forever? You can give her to someone else?” 

“That’s right, I can, whenever I want to.” Daddy sees the fear in his eyes and kisses him quickly. “But not you, sweetheart! You’re my baby boy no matter what. You’ll never, ever go live with someone else. I promise.” 

Stiles sighs in relief. “Kisses,” he demands, and Daddy gives him four bedtime kisses before putting him into his crib. “We’re going to have a playdate with Allison tomorrow,” he whispers. “We’ll see if Kate behaves well enough to play with you both. Goodnight, sweetheart.” 

Stiles smiles and closes his eyes.

__


	5. Chapter 5

**Notes for the Chapter:**

> I know I've been neglecting this story for a long time, but I felt bad that I've been denying all you budding psychopaths (jk jk jk) closure on this story. Please accept this monstrously long chapter as my penance.  
> Also, I'm sorry for all the comments I've been ignoring--I haven't been on here in a long time. But I'm back now, and have a ton of stories backed up that should be posted soon!
> 
> Warnings for this chapter:  
> Non-con body mod  
> Forced minor aunt/niece incest  
> Brainwashed character nursing from another character  
> Scat (character forced to sit in a dirty diaper for a long period of time)  
> Attempted murder and violent thoughts  
> Extreme humiliation  
> Mild racist thoughts towards Kira (I like to make Kate as horrible as possible because it makes me feel like less of a monster for writing this).
> 
> Enjoy!

Kate feels like she’s underwater. Her thoughts are muddled, sounds seem to come from far away, and it’s hard to even open her eyes fully. 

She knows Derek is talking to her, and when she concentrates she can make out every word. “Kate slept all the way through the night, didn’t she? Her big day at the doctor’s office tired her right out. Now she’s all ready for her playdate with her cousin today!” 

Kate feels her temper rise at the thought of spending any more time with Donovan, but then the anger kind of…slips away. It’s hard to hold on to anything. How will she possibly be able to plan an escape now? 

When Derek lifts her out of the bassinet her body is jostled, and an involuntary little sound comes out of her mouth, a soft _baaah_. Derek coos down at her. “Are you trying to talk to Dada? Say, hello, Dada! Good morning!” He kisses her belly and carries her downstairs. 

The playdate must be at their house today. Stiles is crawling around getting out toys, chattering away at Derek as he goes. Derek sits on the couch with Kate cradled in his arms, feeding her one of her bottles. Today, when he puts the nipple in her mouth, she feels herself suck involuntarily, as if that shot yesterday had reignited some long-dormant reflex. 

Stiles finishes with his toys and sits back. He looks hopefully up at Derek, as if he wants to crawl into his lap, then pouts when he sees that Derek’s arms are full with Kate. Kate feels a slight sense of satisfaction at that. Anything that causes that little shit pain is a win for her. 

When the bottle is empty Derek puts her into the bouncer and helps Stiles set up a train set in the middle of the room. The doorbell rings and he leaves the room to answer it. Stiles smiles a little hesitantly at her from across the room. She wishes he would crawl over and try to hold her hand or something so she could hurt him again… 

But then, once again it’s like her anger at him slips away. It terrifies her. Anger _fuels_ Kate; it always has. If they take her ability to hate away, what is she? 

“Look who’s here!” 

Derek returns to the living room. There’s someone in his arms, a tornado of pink and purple tulle. It isn’t Donovan at all—it’s _Allison_. She’s wearing a tutu and a princess crown, clutching a stuffed bunny. 

“Ally!” Stiles sings. “Look! We can play trains!” 

“Trains!” Allison squeals. She kicks her legs until Derek puts her down. “Make it go, make it go!” 

Derek chuckles indulgently. He sets the train up on the tracks for them, then helps Stiles press the remote to make it run. Both Stiles and Allison are completely transfixed by it. 

Kate focuses everything in her on Allison. _Look at me_ , she wills. _Remember who you are, for fuck’s sake._ Allison can _move_ ; she could attack the werewolves if she just tried. 

This is all Chris’ fault. That weak excuse for a man. Look at what a pathetic daughter he raised. 

Her anger rises her in, crests until she feels consumed by it. And then—it’s gone. No, not gone, exactly— _changed._ To a sort of pain in her chest she might have called grief if she had ever felt it before. And just like that she’s bawling her eyes out, wailing like an infant. 

“Oh, poor baby!” Daddy swoops over to pull her from the bouncer. “Is the train too loud for little Katie’s ears? Or did she just need Daddy’s attention?” 

_No!_ she wants to scream. _Of course it isn’t the stupid train! I hate you, and I hate Stiles, and I hate Allison most of all. I hate that she’s an Argent and she’s accepted being here! I hate her, I hate her, and I want to burn her alive!_

Her thoughts race hysterically, the tears pouring out of her. She realizes to her horror that there are other sounds coming out, mixed in with the sobs: babbles that are all mewling little vowels. “ _Ah-aah…na-na-na…_ ” 

Derek sits down with her on the carpet, rocking her in his arms. “Poor Katie,” he says tenderly, wiping her nose with a handkerchief. 

“Did we make her cry?” Allison asks nervously. 

“Oh no, sweetie, she’s just a little baby who likes to cry a lot. Why don’t you come give her a kiss?” 

Allison crawls over hesitantly and presses a wet kiss to Kate’s cheek. “She’s my cousin?” she asks Derek. 

_Of course not, you stupid little bitch! I’m your aunt! Look at me!_

“Yes, your baby cousin. She’s much littler than you are, so it’s important that you show her how to behave. You’re such a good girl, aren’t you, Ally?” 

Allison beams and nods. “I’m Daddy’s _best_ girl! And Mama says I’m her ray of sunshine.” 

“You certainly are,” Derek says fondly. “Oh, your poor cousin is still crying. How should we cheer her up?” 

Allison thinks hard, brow creasing. “Tickles?” 

“I think that’s a wonderful idea! Stiles, come help tickle your baby sister. I know we can get a big smile on that little face!” 

Stiles joins them eagerly, and then their hands are _everywhere_ , tickling under her chin and on her belly. She can hear herself shrieking and squealing, jerking in Derek’s arms, totally unable to control her reaction to it. She even feels herself pee a little as Derek’s fingers dig into her belly. 

“There we go!” Derek says after what feels like several torturous minutes. “We cheered her right up.” 

Allison is giggling wildly, hair everywhere. “Now me!” 

“Tickle monster!” Derek lifts Allison onto his lap, crowding out Kate, and tickles her belly while she laughs happily. Then Stiles wants tickles too, of course, and several minutes go by like that, with Kate feeling herself more and more incredulous at the sound of Allison’s happy laughter. 

She really is brainwashed. There’s no Argent left in her. 

When the stupid tickle pile is finished Derek lifts Kate again. One hand cups her crotch and he frowns. “Hmm. I think Kate went potty in her diaper a little bit. But I think she needs to go some more before I change her.” He looks at Allison and smiles. “Ally, would you like to help your cousin go potty?” 

“Okay!” 

Derek takes of Kate’s onesie, leaving her in nothing but the diaper and the binding around her breasts. He gives her a smile that pretends to be reassuring and then removes the binding too, leaving her breasts completely exposed. “Come here, sweetie. I’m going to push on Kate’s tummy. I want you to squeeze her right here.” He carefully places Allison’s fingers over her nipples. “These little nubs are _very_ sensitive, and if we play with them just right we can help Kate go potty in her diaper.” 

Kate tries to make eye contact with Allison, attempting to get through to her one more time, but it’s impossible. Her own eyes keep sliding away, unable to focus. Allison’s fingers squeeze at her nipples, rubbing them mercilessly. Kate jerks, the sensation going right through her. “Like this, Uncle Derek?” 

“A little harder, sweetie. That’s it, good girl.” Derek pushes at her stomach. Kate hears herself makes sounds again, a mindless little _a-dah-dah._ Allison twists her nipples so hard tears come to Kate’s eyes. 

“Almost there, I think.” Derek puts a hand between her legs and rubs at the fabric of her diaper. His fingers press into her, bringing her to the edge, and she comes, releasing her bladder as she does so. 

“There we go!” Derek lifts her quickly. “We helped make Katie’s diaper nice and wet. Thank you, Ally. Why don’t you and Stiles keep playing with the train set while I get Kate changed?” 

Kate can’t look at Allison any more as Derek carries her out of the room. She can almost feel Derek’s satisfaction, and when he places her down on the changing table he beams at her and gently strokes her cheek with his thumb. 

“You cousin is such a good girl for her Mama and Daddy,” he tells her. “We love her very much. She’s part of the family now. We’ll always take very good care of her. We know she’s not a bad girl like _you_.” 

Kate wants to scream at him, but all that comes out of her mouth is a soft, agreeable, “Bah.” Derek chuckles, changes her, and carries her back downstairs. 

The rest of the playdate passes slowly. Derek plays “wolf” with the other two—they hide, and he crawls around on all four, “hunting” them. Allison shrieks in delight whenever she’s caught. Kate can’t stand it. She wishes she could ask Allison what happened to Chris, whether Allison has ever received any training, if Allison has discovered any weaknesses in the werewolves’ defenses, but she has a terrible feeling that Allison won’t even know what she’s talking about. 

Eventually Stiles and Allison want a nap. Derek gathers all three of them up in his arms and stretches out with them on a blanket so they can nap together in a “puppy pile.” Kate doesn’t want to sleep—being surrounded by a werewolf and two complete idiots sets her nerves on edge—but she feels herself floating away, totally helpless to her own body’s demands. 

They’re still all snuggled in a puppy pile when Scott and Kira return to take Allison home. Allison goes happily into her “Mama’s” arms, still yawning. “Hungry, Mama,” she murmurs, nuzzling at Kira’s collarbone with her nose. 

“All right, princess, Mama will feed you. Derek, do you mind?” 

“Not at all.” Derek lifts Stiles, ignoring Kate as Kira sits on the couch with Allison and starts to unbutton her shirt. “Aunt Kira can feed Allison just like other mommies now,” he explains to Stiles. “Just like our friend yesterday.” 

Kate watches in horror as Kira reveals her full breasts, tipped with a dark nipple. Allison latches on eagerly. Kate can hear the soft snuffling noises she makes as she feeds. Disgust towards her niece floods her. How can she _do_ that? Kira is a werewolf. And God only knows what _breed_ she is—foreign wolves are probably even more vicious than the wolves Kate has dealt with. 

Kira pats Allison’s back contentedly, eyes flickering over to Kate as if she can read her thoughts. “How’s the baby doing?” she asks Derek, nodding to Kate. 

“One day at a time,” Derek says. “She’ll be our little princess someday too, just like Ally.” 

Kate feels tears filling her eyes again. She tries to hold it back, but the feeling of sadness swamps her again and she begins to wail. As Derek pretends to comfort her she watches Allison leave, snuggled oh-so-happily in Scott’s arms. 

X 

Derek is very pleased with how the shot is working. He can still sense Kate’s frustration, but her emotions are all over the place, and she seems much more out-of-it sometimes. 

Things would be damn near perfect if not for Derek’s worries about Stiles. His sweet boy is feeling neglected, he knows, no matter how hard Derek works to make him feel loved. Kate needs so much attention, especially now that the shot has her much more vocal in her displeasure. Stiles is too timid to demand Derek put Kate down and come hold him instead, but Derek can sense his frustration and hurt whenever he’s left alone. 

Derek needs to make it clear that Stiles is his top priority. A few days after Kate’s shot, he decides how to do that. 

Deaton had gone ahead and made an appointment to file Kate’s teeth, a week after he gives her the shot. Derek loads up both his babies to go to Deaton’s office. He doesn’t give Stiles his lap that day and his baby boy is already yawning when they start to drive. Derek glances into his rearview mirror every few moments, loving the sight of both Stiles and Kate in their car seats. 

When they reach the doctor’s office Derek gets Stiles out of the car, hushing him gently when he gives a little half-asleep whimper. “Daddy and Stiles are going to see Dr. Deaton while the dentist takes care of Katie’s teeth,” he whispers to Stiles. “You can nap after we see him, all right?” 

Stiles cracks a worried eye open. “Bad shots?” 

“Just a few, sweetheart. I know my brave boy can handle them.” Derek yanks Kate’s car seat out none too gently and carries both his babies inside the office. 

Kate cries again when Derek hands her off to the dentist, but he tells the dentist to just ignore it. “I don’t want her put under while you work on her teeth,” he tells the dentist firmly. “Just keep her head in a vice so she can’t hurt herself.” 

“Understood.” The dentist lifts Kate into his arms cheerfully. “Come with me now, little one. We need to stop these teeth from doing any nasty biting, yes we do. Wave bye-bye to Daddy!” 

Derek waves at Kate, and the dentist flops her hand in a wave back. Once she’s gone Derek carries Stiles to their appointment with Deaton. 

“Daddy,” Stiles whimpers as they wait in Deaton’s office for him to arrive. “I don’t want bad shots.” 

“Shh, pumpkin. They’re _good_ shots. Daddy won’t let them hurt my sweet boy.” Derek smooths the hair back from Stiles’ forehead. “You know how Kate is a very little baby?” 

“Uh-huh.” 

“Well, she’s a very _bad_ little baby. It makes Daddy think of what a good baby you were, when Deaton gave you shots to help you be very little. Daddy loved taking care of you then. Remember how nice it was, sweetheart? How Daddy took such good care of you and snuggled you every minute and put you to sleep in the bassinet?” 

Stiles nods. He smushes his face into Derek’s neck, eyes shut tight as if he’s trying to remember how it felt. 

“Would you like to be that little again?” 

Stiles’ mouth falls open. “Really?” 

“Really.” 

“B-but what about Kate?” 

“Well, she’ll still be with us. She’ll be your _big_ sister now. She’ll have to get used to Daddy needing to take care of his Stiles first.” Derek kisses the top of Stiles’ head. “What do you think, sweetheart? Should Dr. Deaton come give you your shots? Daddy will take all the pain from them so you won’t feel a thing.” 

“Can I be big again someday?” 

“Of course! It’ll just be for a little while. You’ll be back to playing with your friends and crawling around in no time. It’ll just be a nice little break for you.” 

Stiles thinks about it for a moment, brow creased adorably. “Okay, Daddy.” 

“That’s my beautiful boy.” Derek kisses him again and looks up, smiling, as Deaton enters the room, already holding a prepared syringe. “Everything will be just perfect,” he whispers to Stiles. “Daddy _promises.”_

X 

Kate begins screaming as soon as the dentist releases her from the metal contraption that’s been holding her head still and her mouth open. Tears spill down her cheeks, burning against her sore jaw. 

“Oh, now, let’s not be fussy,” the dentist scolds lightly, undoing the straps on the chair. “Won’t Daddy be so happy when he sees his little girl’s teeth? No more naughty biting!” 

Kate only wails in response. She can’t even move her tongue, to feel exactly what they’ve done to her teeth, but based on the whirring of the tools they must have completely filed her teeth down. It’s so _humiliating._

There is one silver lining: the pain has sharpened her mind. She doesn’t feel nearly so floaty now. The feeling that surges in her chest is _almost_ like the hatred that’s so familiar to her. 

The dentist carries her back down the hall, cooing to her that she’ll get a lollipop if she stops her silly tears. Derek is sitting in the waiting room, Stiles all bundled up in his arms. The little idiot must have fallen asleep or something. 

“All done?” Derek asks the dentist brusquely, taking Kate into his free arm. He doesn’t bother to shift his weight like he normally does and Kate whines loudly, feeling like she’s going to slip right out of his grasp. 

“All done! She was pretty fussy throughout. There might still be some pain in her jaw, that’s why she’s crying.” 

Stiles whimpers a little as Kate keeps wailing and Derek frowns at her. “That’s enough, Kate,” he says sharply. “Your baby brother needs his rest.” 

Kate sniffles back her tears, surprised by Derek’s tone. _Baby brother?_

Derek checks them out at the front desk. Kate gets the promised lollipop, which Derek sticks into her mouth as she tries to strain away. When they get to the car, Derek lays Kate down on the sidewalk and then straps Stiles into Kate’s carseat, the one built like a cradler. “Sh,” he coos when Stiles’ eyes flutter. “Keep napping, my sweet boy.” 

Kate gets strapped into Stiles’ carseat, which keeps her sitting up. Her head lolls against her chest but Derek doesn’t seem to mind. The lollipop slides out of her mouth and Derek clucks in annoyance, sticking it in again. “You’re a big sister now,” he tells Kate. “Stiles got his nice shots from the doctor today to make him a very little baby. Daddy won’t have time to focus on you as much anymore.” 

_Good_ , Kate thinks sourly. Getting a little less attention from Derek sounds perfect to her. She cuts her eyes at Stiles, trying to see if he’s freaked out by losing so much control over his body, but his face is perfectly still and peaceful. 

When they get home Derek takes Stiles out of the car first. “Did someone use their diaper?” he coos. “Let’s get you all changed, sweetheart.” He carries Stiles inside the house, leaving Kate alone in the car. It’s over fifteen minutes before he comes back. He carries Kate into the house, deposits her in the bouncer, and disappears back upstairs. 

Kate tries to enjoy the alone time, attempting to focus her mind on what she would like to do to Allison and Derek and Peter and Stiles if she had her full facilities, but after a while she can feel herself shifting uncomfortably. Is Derek ever going to come downstairs and feed her? 

She can hear herself starting to whine for food. This isn’t _fair_. Derek should be paying attention to her; he should be thinking about all the terrible things she did to him and hating her for them. Why is he _ignoring_ her? 

It’s a relief when he returns to the room. Stiles is in his arms, snuggled up again in a blanket and evidently asleep. Derek places him gently onto the playmat and comes to get Kate out of the bouncer. Just as he’s lifting her Stiles starts awake and begins to cry. 

Derek immediately and unceremoniously drops Kate to the ground. Her head smacks hard against the carpet and she starts to wail too, unable to stop herself. Derek hurries over to Stiles and lifts him again, spouting nonsense little sounds to soothe him. 

Kate is furious. She was about to get food, and now Derek has rushed off to Stiles _again!_ Her wails rise in pitch until she’s nearly screaming. 

“Oh, no,” Derek croons to Stiles. “Is the naughty baby hurting my sweet boy’s ears? Let’s go somewhere she can’t bother us.” He takes Stiles from the room again, leaving Kate helpless on the ground. 

She thinks it must be an hour before Derek finally comes back without Stiles and gives her a bottle. “You’re finally going to move into your nursery. Stiles gets to sleep in the bassinet now.” 

He burps her too quickly, leaving her feeling nauseous, and carries her up to the nursery. The Hales stare down at her from the wall. Kate blinks up at them, feeling her head start to spin. She whimpers, and Derek hushes her brusquely as he changes her diaper. “Daddy’s going to be too busy with your baby brother to wake up with you tonight. So you had special milk to make sure you sleep until morning. But don’t worry.” He drops her into the crib and nods up at the picture on the wall. “Lots of people are watching over you tonight in Daddy’s place.” 

X 

Stiles loves being a little baby. Daddy is there with him _every minute._ Sometimes he cries at the same time as his sister but Daddy always comes to him first and makes him all better. 

One day Stiles is all snuggled in Daddy’s arms on the couch. Daddy is singing a silly song as he counts Stiles’ fingers and toes and Stiles is giggling and feeling like the happiest boy in the world. Kate is on the playmat. She’s been whimpering for a long time and then she starts to cry loudly. 

Daddy looks down at Stiles and sighs exaggeratedly. “Katie’s being such a naughty girl again, isn’t she? Trying to interrupt Daddy’s special time with his favorite boy. Well, she can just keep crying for a while. It’s okay to let bad babies like Kate cry and cry. Daddy would never let _you_ cry and cry, because he loves you _so_ much.” He peppers Stiles’ face with kisses. “Thank goodness Daddy found his perfect little Stiles first. He would be so sad if he was just stuck here with bad little Katie, without his favorite boy to make him so happy. Daddy will _always_ love his little Stiles more than _anyone_.” 

Whenever Stiles is very little it’s like information comes into his head a different way, like it sticks more. He blinks dreamily up at Daddy, feeling Daddy’s words settle deeply into him. Daddy’s right. Kate is _bad_ , and Stiles is Daddy’s perfect boy. There’s no need to ever feel jealous of her. Stiles just feels _sorry_ for her, because Daddy will never love her as much as he loves Stiles. 

Even though he and Kate are both little babies, Stiles gets much better food than her. He gets his yummy flavored bottles, the ones that taste like vanilla and chocolate and strawberry, while Kate just gets boring old plain. “Good babies get special treats,” Daddy explains to him. “Stiles worked so hard to by Daddy’s perfect boy, staying so good even when he was living with those nasty old humans. He _deserves_ nice treats. Bad humans like Kate don’t get to take _any_ of the good things that belong to Stiles.” 

That makes perfect sense to Stiles. He likes thinking that being with Daddy is a reward for what a good boy he was when he was with the bad humans. Kate _should_ see that Daddy loves Stiles more than her, so she knows what a bad girl she is. 

When he’s big again, he’s not going to bother trying to be nice to Katie anymore. She doesn’t get to have any of his toys, not even the dumb ones he never plays with. If Daddy doesn’t really love her, then Stiles doesn’t have to love her either. 

She’s just a bad old human. Hopefully someday Daddy will make her go away for good. 

X 

Kate can’t believe it, but being ignored by Derek is worse than having him fuss over her. She’s hungry all the time, because Derek only bothers to feed her when Stiles is napping. Half of the time he keeps her drugged on _special_ milk so she won’t interrupt his time with Stiles, and he doesn’t bother to try to entertain her in any way. 

That stupid shot he gave her is still working. The worst thing about it is the lack of control it gives her over her own voice. Sometimes, if Derek has ignored her for a long time and her brain is telling her she needs him _now_ , she can hear herself starting to yell for him in an insistent babble. “Ah-na-nah! Dad-na-da! Ba-ba- _ba!”_ Her voice will rise into a shriek, hands involuntarily slapping against the ground. It’s so _humiliating_. 

It’s almost a relief when Derek cheerfully proclaims that the “whole family” is going out for the day. She can’t stand to look at the walls of this house any more. Of course Derek finds the most humiliating outfit for her to wear, an ugly pink onesie with _I <3 Kisses!_ written in flowery script, but whatever. 

They go to the grocery store first. Kate and Stiles are placed together into a shopping cart seat, crammed in close so Kate can feel his warm cheek pressed against her own. People keep stopping Derek to remark on what a beautiful family he has. Stiles beams at all the praise but Kate can fee herself getting agitated. 

She starts to whine loudly, and knows that eventually she won’t be able to stop herself from crying. Derek sighs wearily, as if he should have known she would act up. He carefully takes a pacifier out of Stiles’ mouth and jams it into Kate’s. Stiles giggles and turns his head to snuggle against Kate, drooling all over her cheek. 

After that they go to the toy store so Stiles can get a special present, _of course_. Derek buys him a big stuffed dragon. Kate gets an ugly little rattle. When Derek puts it in her hand she grips it instinctively. It rattles as Derek pushes their double stroller out of the store and Derek bestows a rare smile on her. 

“One more treat today, I think,” Derek coos down at them, reaching in to playfully boop Stiles’ nose. He pushes them into an ice cream store. The air is cool and smells delicious. Kate hears her stomach rumbling. 

She expects that she won’t get anything, but to her surprise Derek orders her a small cup of vanilla. Both she and Stiles are placed into high chairs, with bibs around their neck. 

The first bite of ice cream is so good she almost forgets everything else. But then Derek turns to focus on feeding Stiles and Kate realizes how many other people are in the store, watching all of this happen. She can’t even do anything to make it clear she _hates_ this. 

“Open wide,” Derek coos to her, slipping another bite of ice cream into her mouth. It’s started to melt and it drips down her chin onto the bib. Her frustration with the situation mounts and she can feel her hand slapping at the tray of the high chair. 

“Oh, Katie’s being impatient,” Derek says to Stiles. “She’s _so_ naughty today, isn’t she?” 

Kate tries to spit the next scoop of ice cream back at him, but Derek anticipates her and sticks the spoon deep into her mouth, so her suck-reflex takes over and she swallows the ice cream down. When her bowl is empty Derek completely ignores her so he can focus on feeding Stiles. 

Kate hears a rumbling again—but realizes in horror that it’s her body reacting to the ice cream after so long only having formula. She whimpers, trying to clench her muscles, but there’s no fighting _this_. 

The moment her diaper fills Derek wrinkles his nose, but doesn’t even look at her. She begins to wail, desperate to get his attention. This is _so gross_. 

“Kate’s just going to have to be patient,” Derek coos to Stiles. “Daddy has to make sure all the rest of this ice cream gets into his baby boy’s tummy.” 

The seconds crawl by. Derek goes as slowly as possible in feeding Stiles, acting as though Kate isn’t even there. Her digestive system is still revolting, and every few minutes she feels herself _go_ again, adding to the mess. A feeling of panic rises in her. They still have to drive all the way home before Derek will change her. She can’t take this, she _can’t_ , she _can’t_ … 

“All done!” Derek says, lifting Stiles out of the high chair and nestling him back into the stroller. He takes his team cleaning up their table, then lifts Kate onto his hip. “This messy little girl needs a change, doesn’t she?” he coos. “But it would be too yucky to change you in here where everyone is eating. Let’s go.” 

He carries her out, pushing Stiles in the stroller. When they get outside he doesn’t push them in the direction of the car, but steers the stroller into a grassy spot between the ice cream store and the store next door. He digs in the diaper bag on his free shoulder, then pulls out a blue mat, wipes, powder, and a fresh diaper. 

“Here we go,” he says cheerfully, dropping Kate onto the mat. Horror rises in her as she realizes he’s really going to change her here in public, where anyone walking by can see. Her wails rise in pitch, making Derek cluck his tongue as he cleans her off. 

“Don’t you see how well your brother is behaving?” he scolds her. “Why can’t you be more like him, hmm? If you were a good baby like Stiles, you would get nice treats too.” He replaces the diaper with a fresh one, but when he tries to lift her up her body can’t handle the movement and she feels herself fill the new diaper, too. 

“Bad girl!” Derek scolds. He quickly marches her over to the car and straps her into the carseat, ignoring her screams and flailing arms. Derek hurries back over to Stiles and spends a few minutes rocking him before carrying him over to the car as well. 

The ride home is torturous, with Derek going so slowly Kate is sure it’s on purpose. Just as they reach the house Stiles must fill his diaper too, and starts to whimper. _Then_ Derek hurries, rushing to lift Stiles and carrying him into the house, cooing soothingly at him as he goes. 

Kate is stuck there sitting in her own mess, kicking her legs as if to try and get the diaper off of herself. In her struggles she ends up wetting it too, adding to the terrible discomfort in her lower body. It makes her feel helpless in a way she hasn’t felt before. Derek _has_ to come get her. She can’t just stay here; she _needs_ him. 

She’s just about tired herself out when Derek finally comes back. He hauls her inside like a bag of forgotten groceries and finally cleans her off. “Looks like you’re going to have a rash,” he says coldly. 

Kate whimpers. She feels too tired to do anything else. Derek has made his point. If he decides to just stop taking care of her, she’ll die. She’s completely at his mercy. 

“What’s wrong, Katie?” Derek stares down at her, face inscrutable. “Is Daddy being mean to you?” 

Much to her embarrassment the words make tears fill her eyes. She sniffles and tries to look away from him. 

“It’s hard for Daddy to be nice to his little girl when she doesn’t even _try_ to be good,” Derek tells her patiently. “Sometimes Daddy thinks he’s wasting his time, letting Kate stay here in this nice cozy den. Maybe Katie can’t _ever_ learn how to be good.” His voice is almost mournful by the end. 

Dread fills her. Is he going to give her to Peter, or send her back to the people who captured her? Is this what happens when he finally gets bored with watching her suffer? 

“But maybe… _maybe_ …Daddy is wrong. Maybe Kate _can_ learn how to be good.” Derek looks at her thoughtfully, then lifts her so she’s sitting on the table, at eye level with him. “Daddy knows it’s hard for you to use words right now. But try real hard for Daddy, Kate. Say my name. Show me you’re willing to be my good girl.” 

Kate stares at him. Her thoughts feel all sluggish and confused. A piece of her is whispering that this would be the worst thing she could do, a humiliation so cutting she can never recover—but a bigger part of her is whining that she needs Derek to stop acting this way towards her. She needs just a _little_ affection. That’s not so much to want, is it? 

It takes so much effort just to make her mouth shape the sounds she wants, but Derek is patient, standing over her and waiting for her to do it. “Daaa,” she finally manages. 

“No, Kate. You can do better than that.” 

She squeezes her eyes shut, but Derek doesn’t like that either. “Look at Daddy, Kate. Let’s see those pretty eyes. If you can do it before your brother wakes up from his nap I’ll put nice lotion on your bottom so your rash won’t hurt.” 

_Dada_. She can do it, she knows she can. But God, it hurts to actually give in. What if he expects her to _keep_ saying it? What if the next thing he demands is something worse? She can’t be like Allison or Stiles. She’s stronger than that; she has to be. 

But it comes out suddenly, in a little cry of desperation: “ _Dada!_ ” 

Derek beams. “That’s my good girl! Can you say it again?” 

“Dada,” she wails again, feeling fresh tears in her eyes as the word comes easily. After that it’s like her brain loses the plot completely and she just keeps babbling the same two syllables over and over: “ _Da-da-da-da-da-da-da…”_

Derek picks her up, cradling her close to his chest. “Katie is being such a good girl! Dada is so proud of her!” He tickles her stomach, taking her by surprise and making her squeal. He gives her fresh lotion, as promised, and even tucks her into the crib with a soft blanket. “Dada will be right here as soon as you wake up,” he promises. 

When the next morning comes he’s true to his word, not waiting for her to cry herself out like he has every day since Stiles regressed. Today he’s much nicer to her—he still gives Stiles most of the attention, but he’s gentler when he picks Kate up and he doesn’t mock her when she cries. Only once does he ignore her crying for several minutes. She finally gives in and wails, “Da! Dada!” and he hurries right over. 

Things continue on like that. She has to call him Dada at least once a day. One day he plays peek-a-boo with her, doing it over and over while she stares stonily back at him. Eventually, he sighs and sits back. “Daddy forgot Kate’s not a good baby like her brother,” he says sadly. “Good babies always love to play with their Daddy. Katie’s trying to be naughty again.” 

The thought of having to return to “naughty baby” treatment—the dirty diapers and rough hands and cruel words—is more than she can stand. She gurgles and reaches up for Derek’s hands. Derek tries playing peek-a-boo again and this time she squeals, releasing a peal of laughter. Derek rewards her with kisses all over her face. 

He tries testing her, placing her and Stiles together in the bassinet to nap at one point, standing over them sternly to make sure Kate doesn’t try anything. She sniffles and only snuggles into Stiles, closing her eyes so she can nap. Before she drifts off she hears Derek cooing with delight at how adorable they look, snapping a few pictures with his phone. 

The night, as he feeds them both bottles, he croons to Stiles: “Your baby sister is being a good girl today, isn’t she? Daddy thinks those bad human thoughts might be going away from her head. Maybe soon she won’t even _remember_ what a bad human she used to be. If she forgets how bad she was, we can forget too. Won’t that be good?” 

_Would it?_ Kate imagines Derek treating her just like he does Stiles, genuinely trying to make sure she’s happy and comfortable. Is it even possible? Could Derek really _forget_ what she’d done? 

As soon as the thought comes she scolds herself for it. Of course not. He just said it himself. For Derek to forget, _she_ would have to forget first. And she can’t. She _won’t_. Killing the Hales was her greatest triumph. No matter what they do to her, she won’t forget it. 

The days float by, and soon it’s time for them to return to Deaton’s office. Stiles has started to age up, and is babbling at Derek, not really able to get out any real words but delighting in the way Derek praises every nonsense syllable out of his mouth. 

When Deaton calls them back to his office he coos over Stiles for a minute, then turns to Kate. “Are we renewing her shots today?” he asks. 

“No. Not today.” Derek looks down at her, making direct eye contact in a way that makes her feel frozen. “Kate’s been behaving like a good girl recently,” he says. “I think it’s time to see if she really learned anything. Let’s give her a few more privileges and see if she can be trusted with them.” 

The words shock her so much that she doesn’t even hear Deaton’s response. More privileges? Does that mean she might be able to walk? Feed herself? Talk? She could talk to Allison. She could find out what happened to Chris. She could see if any of it is an act; if Allison might be able to help her escape… 

Her thoughts are interrupted by Derek kissing her forehead. “What do you think, sweet girl? Can you keep being such a good baby for Daddy?” 

“Dada,” she says immediately, gripping Derek’s finger in her fist and nuzzling against his chest without hesitation. 

She can’t screw this up. 

X 

“You’re a fool,” Peter says to Derek two weeks later, disapproval clear in his voice. “It’s much too soon.” 

They’re having a playdate. Donovan is doing a puzzle on the floor, while Stiles, still too young for that kind of play, is napping on Derek’s chest. Kate is on the playmat. She’s able to move her hands and legs now, and she bats at the toys, wanting Derek to see that she’s playing nicely. He said that if she keeps behaving so well he’ll start giving her flavored bottles for dinner with extra protein. That will give her more energy during the day. 

“No, it isn’t. I told you, she’s learning how to behave. We’ve hardly had any problems in the past few weeks.” Derek’s voice is proud. “I think the Society should consider this for every hunter we capture going forward. It’s such a humane way of making sure they can’t hurt anyone.” 

“I don’t think they’ll agree to that. Did you hear they’ve found and destroyed another hunting family in the northeast? About twenty-five, they said. Completely stamped out.” 

“Really? That’s fantastic.” 

“They’re becoming much more proactive. If they keep it up at this rate they should have every major hunting family finished by the end of the year.” 

That can’t be true. Kate knows hundreds of hunters. They have to still be out there, fighting. If all the hunters are dead—who will stop the werewolves from taking over? From infecting humans with their disgusting disease? 

She has to be out there helping them. She has to be part of destroying this cancer. If the werewolves are actively working to stamp out hunters, she has to escape as quickly as possible, not play the long game like she was planning. Fuck trying to team up with Allison. Kate should have known that the only person she can depend on is herself. 

Her thoughts are racing so quickly she can’t pretend to play anymore. She rolls over onto her side—she’s just mastered rolling over— and closes her eyes, pretending to nestle in for a nap. 

“Oh, look at that,” Derek says tenderly. “She’s sleepy. Look how innocent she is now.” 

“She’s playing you.” 

“No, she’s not. I can tell.” 

“Right. Trust Kate. That’s never gone wrong before.” Peter snorts. 

“Hey.” Derek’s voice is suddenly deadly, making Kate tense. “Don’t say that shit to me. I know what I’m doing.” 

“No, you don’t, Derek. She’s going to hurt you, just like before. You’ve always wanted to believe the best in them, but they’ll let you down. They always do.” She hears rustling, and cracks open an eye to see Peter pulling a book of matches out of his pocket. “Every day for the past twelve years I’ve kept matches in my pocket. So I can remember what they did to us, with something so tiny. With something that seemed so _innocent_.” 

Derek’s voice is strangled. “So what, Peter? You still haven’t forgiven me for a mistake I made when I was a teenager?” 

“Not when you continue to make that mistake today. What is it, Derek? You want her to _love_ you? Is that what you regret most from those days, that she never really did? Is _that_ what you want back?” 

Derek snarls and moves so quickly he’s almost a blur. Peter falls over the couch, looking shocked. Stiles, startled awake on Derek’s chest, starts to cry. 

“Get out of my house,” Derek demands, holding Stiles protectively. 

“Gladly.” Peter stands, looking white with surprise but unharmed. “I won’t be back until _she’s_ gone.” 

He collects Donovan and leaves without another word. Derek gently tries to comfort Stiles, apologizing for scaring him. “Let’s go into our rocking chair in the nursery,” he croons, carrying Stiles from the room. 

Kate looks over towards the couch. When Peter had fallen, the matchbook had dropped. It’s laying on the floor now, half-hidden under the couch. 

Will he miss it? Will he come back for it? 

Matches were the first weapon Kate ever wielded. She still remembers her dad teaching her how to use them, how to find something flammable so you didn’t have to lug around kerosene or gas to help the fire spread. There’s so much in Derek’s house she could use. The blankets over the couch, the rug by the kitchen…her heart skips a beat. The flannel of Stiles’s onesie. That would catch nicely. 

She turns her head to make sure Derek isn’t on his way back, and then slowly turns herself on her stomach and begins to drag herself forward. It takes a long, long time, but eventually she reaches the matches. She takes a breath and shoves them as far under the couch as she can, so they can’t be seen without someone directly looking for them. 

There. 

She makes the crawl back to the playmat as quickly as possible and pretends to nestle in for a nap again. Her heart is jackhammering and she takes deep breaths so Derek won’t be able to hear. 

She has matches. She has the beginnings of a plan. 

She’s going to get out of here. 

X 

She can’t think of anything else except the matches for the rest of the day. She can’t waste this opportunity; if Derek catches her with them she knows there’ll be no saving herself. 

But the most lovely visions dance in her head. She has to make sure Stiles burns to death. It would be ideal if she could do it while Derek is out of the house. He’ll be so desperate to get inside and rescue Stiles that she’ll be able to slip away into the woods. She doesn’t know how far it is to civilization, but she can make it. Even if she has to crawl the whole way, she’ll make it. 

And even if she doesn’t, that’s okay too. It’s still a win for her if they catch her after Derek’s house burns. To know that she took his family away a second time is the best thing she could possibly hope for. 

Derek seems a little tired and distracted after his fight with Peter. After he feeds them dinner he cuddles with both of them on the couch, rhythmically patting each of their backs in turn. When his phone rings he sighs and answers it: “What?” 

Kate can hear an excited female voice on the other end. Derek sits up, jostling Stiles and making him whimper. “Erica, slow down. What’s…are you sure? He won’t shift back? Do you think it’s an Omega? Oh, God. No, I’ll come take care of it. Can you…okay. Okay!” He hangs up and quickly lifts Kate off his chest, settling her onto the floor. “Sweetheart,” he says gently as he rouses Stiles. “Dada has to go help a sick wolf who just found his way into our community. Nap on the couch, pumpkin. Daddy will be back as quick as he can.” He kisses Stiles, then leans down to kiss Kate. “Daddy doesn’t have time to put you in your crib, Katie. Behave while Daddy is gone or you’ll be a very sorry little girl.” 

Kate blows a spit bubble at him to convince him of her trustworthiness, but he seems too distracted to even notice. He doesn’t even give Stiles a dozen kisses before he leaves like he usually does, just hurriedly heads out the door. 

This…this is a _miracle._

Kate has never been religious. A lot of hunters are. They think it’s their sacred duty from God to rid the world of monsters. For Kate the pleasure of killing wasn’t theological, just primal. She liked knowing what kind of power she could wield over the allegedly dominant species. 

But even she has to think: God is on her side. God wants this place to burn. 

God has engineered all of this for her. 

She wants to be as smart as possible about this. She practices crawling to the door first, rising up onto her knees to make sure she can turn the knob. It’s easy. Easier than she expected, even. Derek must not know how quickly she’s regained her strength or he never would have left her alone. 

Maybe she’s superior to the other humans they keep here. That’s probably it. She’s recovered from their poisons much quicker than expected. 

She crawls back to the couch and tugs on Stiles’s arm. His eyes crack open and he gives her a sleepy, sweet smile. She tugs again and he slides off the couch to the carpet. His mouth opens in shock and his eyes fill with tears, but she hurridly presses her finger to his lips. As he watches her warily she reaches under the couch and pulls out the matches. 

She isn’t sure whether Stiles knows what they are or not, so she turns towards him with her brightest smile and waves the matchbook at him. “Play!” she chirps. 

Stiles beams in delight. Kate tugs at the blanket on top of the couch. There are little tassels on it, perfect for starting a fire. 

Her hands shake a little as she flips open the matchbook and she takes deep breaths, needing to get this right. She’ll light the blanket on fire first. Then, once it’s in flames, she’ll light Stiles’s onesie. She’ll pull the blanket over him, to make sure he burns nice and painfully, choking on smoke and unable to put the fire out. Then, with his screams ringing in her ears, she’ll head for the door. Hopefully as Stiles flails around he’ll light the couch and rug on fire. It would be nice if the whole house goes down, but murdering Stiles will be enough. 

She grabs Stiles’ leg and tugs him towards her. He just keeps beaming, obviously pleased that his sister finally wants to play with him. She wishes she could really talk to him, lean in close and explain that it’s his precious Daddy’s fault that he’s about to die. 

Well, at least she knows that’s the truth. 

She pulls the match out of the book, takes a deep breath, and drags it against the top, tears of joy filling her eyes as it lights. 

Then she hears Stiles chirp: “Dada!” 

The match falls from her fingers to the floors, where it’s extinguished in an impotent little puff. She turns her head to see Derek and Peter standing in the kitchen doorway. Peter is smirking, while Derek’s face is just blank. They must have come in through the kitchen door. Kate hadn’t heard a thing. 

“You were right,” Derek says to Peter. “She really is that stupid.” 

“It’s amazing,” Peter agrees. “Even Donovan figured out it was a setup. When we got home he asked why I was ‘pretending to fight with Uncle Derek.’” He snorts, shaking his head in mock astonishment. “But she just so desperately wanted to believe.” 

Kate stares at them, mouth hanging open. The fight had been _fake?_ So then the matches…Peter had dropped them on _purpose_. There was no omega wolf. Derek must have immediately slipped around to the back and reentered the house with Peter. 

This was all just a test. 

Derek strides across the room and grabs her hand, pulling the matches away. Kate screams, losing her head completely. _“No! Nooo!_ ” she wails, thrashing frantically. 

Derek lifts her, trapping her hands at her sides. “We gave you so many chances, Kate,” he says coldly. “No one can say we didn’t. But you’ll never get better. You’ll never be a good baby for me, will you?” His fingers dig painfully into her. 

She spits at him, kicking her feet. It isn’t fair. She’d wanted this so badly. She’d wanted to hear Stiles cry. She’d wanted to imagine Derek sobbing over the ruins of his home. And now it’s all gone. 

“No,” Derek says. “You’ll never be good.” His hands are rough as they hold her down, face empty of pity as he stares down at her. When he speaks again, his voice is quiet. “So what should we do with you now?”

**Notes for the Chapter:**

> I'm planning to make the final chapter three alternate endings: a "bad" ending where Kate goes to Peter; a "worse" ending where Kate goes to Deucalion, and a "worst" ending where Kate stays with Derek and Stiles as Stiles's new doll. Any other variation you'd like to see, or anything else you'd like to see before this universe closes up shop, sound off in the comments.


	6. Chapter 6

**Notes for the Chapter:**

> Thank you to everyone who gave me ideas for this story! I hope you enjoy the three alternate endings! This is far and away the most extreme stuff I've ever written, or even ever seen on the Archive, so please read responsibly. I've put warnings for each separate story within the text.

**Peter’s Baby Girl**  
_Warnings: Non-consensual body modification; watersports, scat, sexual abuse, forced bestiality, forced orgasm, forcefeeding_

**One Year Later**

Today marks one year since Kate’s adoption ceremony. After Derek had caught her with matches he’d packed her in the car and driven her to some sort of administrative center, where he and Peter had signed some papers in front of a clerk. Then Peter turned to her, beaming, and lifted her out of Derek’s arms. 

“You belong to me now, little girl. Time to go home!” 

At first, Kate had stupidly thought things wouldn’t be so bad. After all, Derek had put her through so much, she hadn’t imagined things could get much worse. 

She was wrong. 

“Katie!” Peter lifts her out of her crib, beaming. “It’s our celebration day! One year since you came to live with Papa. Isn’t that nice?” 

Kate gurgles at him. Way back when he first took her, Peter had had an operation done to her, something with her salivary glands so she’s always drooling all over herself. 

Peter takes her over to the changing table, removes the diaper, and cleans her off, then carries her downstairs, completely naked. “All right, princess. Since it’s such a special day, you can start your playtime before breakfast. Into your bouncer!” 

The bouncer has been specially made by Peter himself. Attached to the seat there’s a vibrator, short but the width of a coke cake, and, further back, a huge glass dildo. 

“Let’s slick these up so our little princess is nice and comfy.” Peter picks up the jar of Icy Hot he keeps by the bouncer and slathers liberal amounts of both toys. “Perfect!” He carefully lowers her into the seat. He never bothers to stretch her beforehand, just forces her down so both toys slam inside of her. Her hands are tied to the side and clamps are attached to her nipples. She squirms at the burn of the Icy Hot, feeling her eyes start to water. 

“There!” Peter uses a remote to start the bouncer. Kate feels the toys whirring, moving up and down inside of her. Her mouth hangs open stupidly and Peter chuckles. 

“Have fun, princess!” 

He leaves to go wake up Donovan. Kate knows he won’t be back for a long, long time. He leaves her in the bouncer for hours sometimes, forcing multiple orgasms out of her before finally coming back to ask her with a big smile if she’s having fun. 

She comes with a gasp after about ten minutes. The bouncer never lets up, only intensifies. Peter never likes to watch her actually come, but only come in after she’s been driven completely to exhaustion. 

Unlike Derek, he never actually makes her come himself, but tries to remove himself from her body as much as possible. He touches her during diaper changes as clinically as possible. The only time he ever really touches her vagina is when he wants to give his dog, Phoenix, a special treat. He pushes dog treats inside of her and calls over his pet, who tugs at her with his teeth, lapping at her sloppily until he gets them out. He’s done it enough times that now the dog expects it, and will sometimes come over to wherever she’s lying and sticks his wet nose around her thighs to see if anything’s there. 

Peter loves that, of course. He’s started talking about having Phoenix out to stud and using Kate as his hump pillow. “She loves playing with her puppy,” he’d explained to Derek the last time he brought Stiles over for a playdate. Derek only chuckled and shook his head, not even looking at Kate. 

Sometimes she wants to beg Derek to take her back, or as least stop Peter from the absolute worst things he does. But Derek was done with her the moment she grabbed those matches. He always ignores her whenever he’s over, instead just looking at Stiles with that soft look of love Kate hates so much. 

Stiles had been confused the first time he was over, wondering why Kate wasn’t his baby sister anymore. But now he just ignores her too, playing with Donovan happily as Kate is bounced up and down on the dildo. 

Kate can hear Donovan being fed his breakfast, and then he charges into the living room to play with his trains. He hates her and spends most of his time poking her, smacking her, or throwing toys at her, but today he focuses on his toys. Even he’s starting to treat Kate like she isn’t even here. 

The bouncer continues to whir. Kate feels drool dripping down her chin as the dildo starts its deep, stabbing thrusts, the ones that feel like they’re going to rip her in half. 

“Daddy!” Donovan calls. “I went potty!” 

Kate’s heart sinks. 

One of the first things Peter did to show he favored Donovan was decree that he wanted to save money on diapers, so Kate wouldn’t be getting any new ones. Instead, whenever Donovan needs to be changed, his dirty diaper is placed on Kate. She hasn’t had a clean diaper in a year. 

She constantly has some sort of diaper rash, but Peter almost never bothers cleaning it. Whenever she gets sick he’ll use a baby aspirator to suction out her nose, smears Vicks all over her, and will sometimes turn her over on his knee and smack her back hard to “clear out her chest,” but never actually gives her medicine or takes her to the doctor. 

Half the time the waste in the diaper spills out because the diaper is too full. Whenever that happens Peter scolds her for being such a messy girl and spanks her, hard, until she’s choking on tears. 

Peter comes into the room already armed with a fresh diaper, powder, and cream for Donovan. He plucks Kate out of the bouncer without any warning or preparation. He removes the diaper from Donovan and quickly tapes it shut on Kate before returning to lavish attention on the boy. 

Kate starts to cry. Her mouth hangs open and she hears sniffling little wails come out of it. She stopped fighting tears a long time ago. They make her feel better, and her pride disappeared a long time ago, so why bother trying to hide them? 

“Oh, hush,” Peter says irritably. He fishes a pacifier out of his pocket and jams it into her mouth. She can’t hang onto it herself anymore—Peter had her teeth removed months ago. Instead, her pacifiers have clamps which attach to her nostrils. It’s hard to breathe whenever they’re in, but Peter never cares. 

After that, Peter ignores her for a while. Donovan is a little huffy that Kate is lying right in his playspace, so he shoves her out of the way a little and then ignores her too. He never tries to get her to play like Stiles used to. 

Kate’s mind wanders to Allison, as it often does when she’s left along with her thoughts. She hasn’t seen her niece since she came to live with Peter. Apparently Scott thinks she would be “too upset” to see how Kate “needs to be treated,” so whenever they have a playdate they go to Scott and Kira’s house and leave Kate behind. “You’ll never see her again,” Peter promised Kate a year ago, and that’s held true. 

After several hours Peter comes in and takes Kate into the kitchen. She usually only gets one bottle a day; Peter likes to keep her hungry. 

“What special treat should we put in my girl’s bottle today?” Peter says cheerfully as he starts to prepare the formula. He always adds a little something to Kate’s bottle—wasabi, raw eggs, turmeric. Today it’s hot sauce. He pours in several spoonfuls before bringing the bottle to Kate’s lips. 

She’s tried to fight him before and it’s only resulted in force feeding. When he’s feeling particularly nasty Peter will place her on the floor with a ring gag holding her mouth open and suspends the bottle in a little contraption over her, so the formula drips into her mouth over the course of hours. 

It’s easier just to obey. 

She gags a little as she drinks, but she’s mostly gotten used to it by now. Peter kisses her cheek, then carries her upstairs. 

Her bassinet has also been modified to fit Peter’s specifications. Inside of it there’s a vibrator on a little stand, kept raised about two inches perpendicular to the cot. It slides neatly inside of her every night. Peter strips off the diaper and onesie before maneuvering her into the bassinet, then starts the vibrator up. “I’ll see you for second bedtime!” he says cheerfully. 

This is “first bedtime,” when the bassinet fucks her for hours on end until she’s so exhausted she falls asleep with it still whizzing inside of her. Before Peter goes to bed himself he’ll come in, wake her up, put the filthy diaper back on, and put her back to bed. 

Sure enough, she feels herself drifting off to sleep after about two hours. 

Then, suddenly, she’s jolted awake by a wailing sound. After a disoriented few minutes he realizes what it is: a smoke alarm. She can hear Donovan wailing, and Peter’s running footsteps. He goes into Donovan’s nursery, then comes out again. His footsteps pass right by Kate’s door as the alarm continues to blare. The front door slams shut. 

Panic spreads through her. Is he leaving her alone? Is the house going to burn down with her inside? She begins to scream, unable to stop until, after several minutes, the alarm shuts down. 

She’s sobbing with exhaustion and fear when Peter finally comes into the nursery. He coos when he sees her and lifts her from the bassinet. “Aww. It was only a little malfunction with the alarm, little one.” He pats her back. “Did you think Papa just left you here? That was pretty scary, wasn’t it?” 

She sniffles, resting her head against his chest. 

“Well, Katie, let me tell you something. Papa’s going to make a promise to his little girl, and Papas never break a promise. I’m not saying when, or how exactly, but someday…when Papa isn’t having any more fun keeping you here…” his hips sway back and forth, mock-soothing her, and his lips are a centimeter from her ear as he snarls: “ _I’m going to make sure you burn._ ” 

Kate gurgles at him, as if she’s agreeing. Peter kisses her forehead, then puts the diaper back on her. “Oh, yes,” he says cheerfully as he tapes it up. “A nice big bonfire, or maybe a little party at the crematorium, or a night when I put you to bed in the fireplace and light it up so Donovan and I can be nice and warm. Someday, little princess, you’re going to burn to death, and we’re all going to watch. So you should hope Papa doesn’t get bored with you anytime soon!” 

He puts her in the bassinet, blows her a kiss, and leaves. Kate continues to cry, soaking the cot of the bassinet, unable to sleep for the rest of the night. 

**The Alpha Pack’s Girl**

_Warnings: Extreme non-con body mod, rape, forced pregnancy, discussion of forced abortion_

After Peter and Derek catch Kate with matches, Peter restrains Kate in his arms while Derek goes into the kitchen to make a call. He comes back a few minutes later, looking satisfied. “He’s on his way.” 

“Good.” Peter looks down at Kate coldly. “Well, I guess this is goodbye, Kate. It hasn’t been a pleasure knowing you, but it’s certainly a pleasure thinking about what will happen to you now.” He looks up at Derek pleasantly. “Derek? Any final words for this dear girl?” 

Derek shakes his head. He’s turned his attention back to Stiles, cuddling him tightly in his arms and cooing down at him. Kate hates the idea that this is how she has to see Derek for the last time—so deeply in love with his brainwashed human. 

Where are they sending her? Is she going to die? Will she ever see Allison again? 

Peter hears her heartrate rising and chuckles. “Oh, don’t be scared, sweetheart. You’re not going to get anything you don’t deserve.” 

The next ten minutes are interminable. Finally there’s a knock on the door and Derek goes to answer it. 

“Hey, Ennis. Come on in.” 

A man Kate has never seen before walks in. He’s built like a bull and miserable-looking, eyes hard and mean. “Just to be clear, this is permanent,” he says coldly to Derek. “You can’t just take her back next week because you change your mind.” 

“I know. I don’t want her back. If you hadn’t offered I would have just put her down tonight, so you’re really doing me a favor.” 

“And there won’t be any problems between our packs if you…disagree with our treatment of her?” 

“I don’t care how you treat her. I don’t care if you call me tomorrow and tell me you tore her throat out.” 

“Good. Let’s load her up.” 

Peter takes Kate out to Ennis’ car. She expects there to be another stupid car seat, but the backseat is empty. Peter simply tosses her inside like a piece of luggage, shakes hands with Ennis, and goes back inside the house. 

When Ennis gets in the car there’s no cooing or soft words or any of the pretend affection Derek used to show. He just starts driving silently, not even glancing at her. 

Kate still has some ability to move. She stretches her hand towards the car door handle, wondering if she can jump out and crawl away. Suddenly there’s a sharp pain in her shoulder and she cries out, looking up to see that Ennis has silently reached back and sunk a claw into her to drag her back into the seat. 

She lies still after that, quaking. Ennis stays quiet until the car finally stops, and then he comes to get her. His hands are rough and when he carries her he just kind of lugs her, instead of lifting her gently like she’s a baby. They’re heading towards a house that’s dimly lit. Through the window she can see several people sitting around, waiting for them. 

Suddenly she misses Derek fiercely. She’s about to be carried helplessly into a house full of strange werewolves who clearly have no plans to carry on Derek’s fantasies. She doesn’t know what they’re going to do to her, but she’s sure it’s going to be awful. 

“Got her,” Ennis calls as he comes into the house. “Hale said he doesn’t care what happens to her. We’re fine.” He takes her into the living room, then drops her unceremoniously on the floor. 

“Good. Did she give you any trouble?” The voice comes from a tall man sitting in a plush armchair. He’s wearing dark glasses and there’s a cane leaning against his chair. He radiates a cold sort of power. It surprises her—she’s gotten pretty good at recognizing werewolf dynamics, and she’d thought Ennis seemed like an alpha, but this man is clearly in charge. 

Then something tickles at the back of her memory. There had been some story about a powerful new pack, all made up of alphas. Their leader had been blind. The Alpha Pack. Her hunting team had searched for them for a long time, but when there was no news it had been assumed the whole thing was just a rumor. 

Terror spreads through her. These are the most notorious werewolves in the world, and now they control her. 

“Yeah, she did. Tried to get out of the car.” 

“Well, what can you expect from such a little parasite?” Deucalion’s voice is disgusted. “Let’s get the kanima venom. Might as well make things easy.” 

The woman leaves the room. When she returns moments later she’s holding a syringe. Kate tries to crawl away, but the woman places a knee on her back, holding her in place. There’s a sharp pain at her neck and it feels like thick black tar spreads through her. She’s paralyzed. Her eyes flutter closed, mouth open and pressed against the floor. 

“Good,” the main alpha says. “We’ll take her to Deaton in the morning. Thank you, Ennis.” 

They leave the room without another word to or about her, stepping around her like she’s trash. Kate is left on the ground, unable to move the entire night. 

X 

The next morning she’s loaded up in Ennis’ car again. The entire pack comes, so she’s just tossed on the floor at their feet, still kept paralyzed by the venom. When they carry her into Deaton’s office they don’t bother to shield her, so her head smacks against the door. 

“Oh my,” Deaton’s calmly amused voice says. “I see Derek has given you a present?” 

“We took it as charity,” the main alpha says drily. 

“I hadn’t thought you were interested in a human, Deucalion.” 

“Well, I don’t want a little pet like the others.” Deucalion’s voice is disdainful. “But I _do_ have some use for a human, and the Society won’t let me take a normal one. Fortunately, no one cares what happens to this little rodent.” 

“What do you have in mind?” 

“We need to grow our pack. We need a second generation, or the pack will die off. It’s too much to ask of Kali. If we each take turns with this one, we can have a good-sized litter in no time.” 

“Ah!” Deaton sounds pleased as he understands. “You’d like to impregnate her. Well, you surely don’t need my help for that.” 

“We want to make sure the baby is a werewolf. Can you guarantee it?” 

“Not unless you turn her. Statistically, it’s much more likely that a human-werewolf mating will produce a werewolf child, but there’s always a chance…” 

“I don’t want to turn her. She doesn’t deserve that gift. Will you be able to tell what the baby is before it’s born?” 

“Yes. We can test for it at about six weeks.” 

“And if it’s human, we can just terminate and try again?” 

“Of course.” 

“Well, good. That’s what we needed to know.” Deucalion’s finger taps against Kate’s arm as if he’s thinking. “We’re planning to keep her still with kanima venom. Will it be risky, once she’s pregnant?” 

“It can be,” Deaton says slowly. “Do you want her kept paralyzed permanently? If you’re positive you never want her to move or speak again I can make that happen. It’s irreversible, so you need to be completely sure.” 

“I’m sure,” Deucalion says immediately. “Do it.” 

“Let me just get my nurse. This is actually quite exciting for me, I so rarely get to try these methods with the humans here.” There’s a long pause, and then Deaton’s voice again. “This is a kanima-based poison. It’s only been tested on animals, but I don’t think there should be any ill side effects. She’ll still be able to breathe on her own, but she won’t be able to blink or move. Her eyes are already shut, so we won’t have to worry there. You’ll have to force-feed her to keep the pups healthy.” 

“Fine.” 

“Hold out her arm.” 

The needle sinks into her, and the scream Kate feels trapped in her chest never comes to the surface. 

X 

That night, she’s undressed and placed on a couch. She had heard them discussing an order. Deucalion gets to be the first to impregnate her. Ennis will be next. The woman, Kali, is allowed to “play” with Kate whenever she wants. 

She hears footsteps coming towards her, and then Deucalion is climbing on top of her. He thrusts into her roughly, his movements almost workmanlike, and comes after only a few moments. He wipes himself off using her hair and strides away, never speaking a word to her or touching her more than necessary. 

She can’t even cry. 

X 

Weeks later, they take her to Deaton. Gel is squirted on her stomach and she feels Deaton moving around an ultrasound wand. 

Congratulations,” Deaton says warmly. “A lovely little werewolf pup will be joining your pack.” 

X 

Every day is the same. 

They use the same formula to feed her as Derek used to have. She can’t suck on her own, so they use a spoon to feed it to her , stuck deep in the back of her throat to get her to swallow. She’s kept in a diaper that’s only changed once a night. Every few days they haul her outside and hose her off. 

They don’t fuck her while she’s pregnant. But sometimes—usually late at night, as if they wake up frustrated and need release—one of them will come downstairs and lazily fuck into her mouth until they come. Or Kali will climb on top of her face, dragging her wet cunt over Kate’s nose and mouth until she shudders out her orgasm. 

She feels her body changing, expanding. She wills it every day to be strong and expels the horrible creature inside of her, but the beast is strong. She imagines with horror what the creature with her DNA will do to the world. 

They never speak to her, but they touch her constantly, running their hands proudly over the lump in her stomach. When it starts to kick they delight in the movements, praising it for bruising Kate’s stomach so badly. “You see, it’s strong,” Deucalion says proudly. “And it already hates humans.” 

When it’s ready to be born they take her back to Deaton. He cuts it out of her, not bothering to use anesthetic—she can only bear the terrible pain silently, without moving. Its cries are lusty, like howls, and her entire being aches to kill it. 

Her eyelids are never lifted so she can look at it, and it’s never placed on her bare skin so she can bond. Instead it’s taken away and given to the pack members. The only time she has any contact with it is when it’s placed to her breast, its greedy mouth finding her nipple and suckling at her. She never has any peace after that. They bring it to her to feed every hour of the day and night, cooing to it about a fine hungry boy it is. 

Two weeks later, Ennis climbs on top of her and thrusts until he spills his seed deep inside of her, and it all begins again. 

X 

Weeks turn to months and months turn to years and nothing changes. She bears a child for each male member of the pack. When the last is done she wonders if she can finally be free, but instead the process begins again with Deucalion. 

The pups are taught to see her as nothing but a milk machine. They continue to feed well into their toddler years, their sharp teeth tearing at her breasts. They fight over her milk like wild animals, snarling and snuffling in their desperation to feed. Her eyes have been kept shut since she came to Deucalion, so she doesn’t know what they look like, but she imagines them like half-human beasts, with proud Argent eyes that turn yellow when the moon is full. 

She can hear them sometimes, being lectured by the pack on the evils of humans. “They must be killed,” Kali will tell them. “Or kept for some purpose useful to werewolves, like the human we keep. But we only do that for as long as they’re useful. What should we do to the human in our pack, once we’re done using it?” 

“Kill it!” the pups chorus. 

She wishes they would. 

X 

She’s nearly reached the end of her fifth pregnancy. Deucalion and Ennis are in the room, touching her, discussing when they should bring her to Deaton. 

“I saw Hale the other day,” Ennis suddenly says casually. “When I was out with the pups. He said they barely looked like her.” 

Kate’s heart skips a beat. Derek. She has been thinking about him a lot lately. She had wondered if he still remembered her, if he knew what they’d done to her. She had thought he surely couldn’t. He wouldn’t stand for it, would he? 

Apparently he does know. He’s letting this happen to her. 

She doesn’t even understand why that hurts so much. 

“I hope you thanked him again for letting us have her.” 

“Of course.” Ennis pauses. “It’s not so bad, having it here. I had thought keeping a human in the house would drive me insane, but…you almost forget its even alive, don’t you?” 

“Yes. I can’t say I won’t take some pleasure in putting it down, though. Once we’re done with it.” 

“And when will that be? How many pups do you want?” 

“Hmm.” Deucalion’s hand slides possessively over her belly again. “Remind me. How many werewolves died in the Hale fire?” 

“Eleven.” 

“Then I think…twelve pups is the right number.” 

Ennis makes a sound of agreement. Deucalion pats her, waking the pup up so it starts to kick. The alphas walk away slowly, already having moved on to some other topic of conversation. Kate is left alone, the monster inside of her pummeling her from the inside out. 

**Stiles’ Doll**

_Warnings: Extreme dehumanization, extreme non-con body mod, extreme sexual abuse, forced incest, disturbing language, implied character death_

Stiles became so much happier when Kate stopped being his baby sister and became his doll. She can’t move or talk or do anything now, because she’s not a real person anymore, just a toy. Daddy said that since the doll couldn’t even blink its eyes its real eyeballs would dry out, so they took those away and gave it pretty blue glass eyes instead. 

His doll has its own special toybox where it stays when Stiles isn’t playing with it. Daddy gives it food through a tube and cleans it when Stiles is asleep. Since his doll is so special Daddy said it won’t last forever and it’s very breakable. Stiles has to be careful with it because once it’s gone Daddy said he can’t ever get another one. But that’s okay. He has lots of toys, the doll isn’t even his favorite. 

He plays dress-up with it and has tea parties with it. Daddy buys him lots of clothes for it, princess dresses and cowboy clothes and _everything_. Stiles knows that Daddy likes watching him play with his doll, so he plays with it a little every day. 

When the doll had its operation to stop it from being his little sister, Daddy made it so real milk comes out of its nubs, so Stiles can have a snack from it any time he wants. It’s yummy. Sometimes he wants lots and lots, and it starts to run out, but if he nibbles and bites down where the doll is fattest it starts to come again. Daddy taught if that if he rubs between the doll’s legs the milk will be warmer, which he likes a lot. 

The doll also replaces Huggie Bear. When Stiles has been a good boy Daddy will bring it over to the changing table so Stiles can rub his pee-pee all over it until he comes. He likes the doll even better than his bear for that, since it’s nice and warm. 

When Allison comes over she loves to play with the doll, too. She’s never had a Huggie Bear, but Daddy and Uncle Scott teach her how she can use the doll to make herself feel good. She can sit on its face, bumping her yum-yum over its nose, rubbing hard over it until she feels very nice. Or sometimes she uses its hands, poking its fingers into her, rubbing them all up and down her special parts. 

One day they come up with a fun game. They’re playing with Stiles’ scuba men and decide the hole in the doll’s legs can be a sea cave for the scuba men to explore, since it’s all wet and squishy in there. It stretches out the doll a little bit but that’s okay, Daddy says it will go back to normal. Allison likes to make the scuba men go in and out. Stiles accidently leaves one of his scuba men inside the doll all night and doesn’t find it until the next day! 

At Stiles’ next birthday party, everybody gets to play with the doll. Daddy has a special new attachment for it that goes over its mouth, and all of Stiles’ friends can use it to feel good. The contraption has a buzzy toy attached to it that can go in Stiles’ bottom or Ally’s special parts. They can bounce up and down on it until they squirt all over the doll’s face and chest. Daddy cleans it up after each person is done using it and then someone else gets a turn. Ally likes it the most, since the toy can go really far inside her. Daddy promises Ally can use the buzzer with the doll every time she comes over. 

One day Daddy tells him that his doll is going to be a special potty-training doll for a while, because Stiles is going to start wearing Pull-Ups. He can’t play dress-up with it for a while. Instead Daddy keeps it in the bathtub. Whenever Stiles needs to go potty Daddy helps him put his pee-pee into the hole between the doll’s legs. 

Stiles loves his new potty. It’s nice and warm. Sometimes he has to sit there a long time and wait for his tinkles to come out so it’s nice to be able to sit comfortably. And since the whole doll is his potty it’s okay if he doesn’t quite make it in time, like when Daddy has to rush him over quickly and hurry to try and fit him inside of the hole. Instead he can just go tinkle all over the doll’s face and chest. 

They use the doll as a potty for a while, under Daddy decides they’re all done with potty-training and Stiles goes back into his diapers. The doll gets a very thorough cleaning and then Stiles can play with it again. 

Eventually Daddy tells him that his doll is too old to play with anymore. It’s not going to last much longer Daddy tells him, and it wouldn’t be sanitary to keep it once its parts stop working. Stiles has one last tea party with it and then Daddy puts it into the garbage bag. Stiles waves bye-bye as Daddy takes it out to the curb so the garbage men can take it to the dump. 

“I’m sorry we had to throw your doll away, sweetheart,” Daddy says once he comes back in. “It was just better not to wait until it stopped working.” 

“That’s okay, Daddy.” Stiles lifts his arms so Daddy will pick him up and cuddle him. He frowns, a funny thought coming to his mind. “It’s not going to come back as my baby sister again, is it?” 

“Oh, no, sweetheart! We’re all done with baby sisters now. The garbage men take all the trash away and put it in a furnace to get rid of it forever. It can’t ever come back.” 

“That’s good.” Stiles yawns. Next time Ally comes over he can give her all the dress-up clothes that went with his doll. They should fit her. They can play princess and knight with his dress up box. 

“And now it’s just Stiles and Daddy again. Just the way it should be, isn’t that right?” 

Stiles giggles, sometimes Daddy says the silliest things. “Daddy, it was just the two of us for forever! It wasn’t a real person anymore, just a toy.” 

That makes Daddy laugh. “That’s true, pumpkin. You’re so smart.” He gives Stiles a big kiss. “I think it’s time for your nap now, isn’t it? And you know what? I think you should get…three stories before you go into your crib. How does that sound?” 

“Wow!” Usually Stiles has to beg to even get _two_ stories. “Why, Daddy?” 

“Because Daddy is just very, very happy today.” Daddy smacks a big kiss on his cheek. His face looks so smiley and peaceful, it makes Stiles beam too. 

Stiles snuggles into Daddy’s shoulder as Daddy carries him upstairs. He can see out the window. It’s started to rain outside. Daddy hasn’t tied the trash bag on the curb shut like he normally does. Stiles almost tells Daddy that his doll must be getting wet, since he wasn’t supposed to ever take it out in the rain, but then he realizes that’s silly. It’s just an old toy, after all. Who cares what happens to it now?


End file.
